CA2390817A1 - Method for the moderately secure transmission of electronic mail - Google Patents
Method for the moderately secure transmission of electronic mail Download PDFInfo
- Publication number
- CA2390817A1 CA2390817A1 CA002390817A CA2390817A CA2390817A1 CA 2390817 A1 CA2390817 A1 CA 2390817A1 CA 002390817 A CA002390817 A CA 002390817A CA 2390817 A CA2390817 A CA 2390817A CA 2390817 A1 CA2390817 A1 CA 2390817A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L63/00—Network architectures or network communication protocols for network security
- H04L63/02—Network architectures or network communication protocols for network security for separating internal from external traffic, e.g. firewalls
- H04L63/0281—Proxies
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L51/00—User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
- H04L51/48—Message addressing, e.g. address format or anonymous messages, aliases
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L63/00—Network architectures or network communication protocols for network security
- H04L63/04—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks
- H04L63/0428—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks wherein the data content is protected, e.g. by encrypting or encapsulating the payload
- H04L63/0442—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks wherein the data content is protected, e.g. by encrypting or encapsulating the payload wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Computer Hardware Design (AREA)
- Computer Security & Cryptography (AREA)
- Computing Systems (AREA)
- General Engineering & Computer Science (AREA)
- Data Exchanges In Wide-Area Networks (AREA)
- Information Transfer Between Computers (AREA)
Abstract
Software and process that provides a moderately secure, easy to use, fully automatic and transparent means of sending and receiving electronic mail ("email") via the Internet using public-key cryptography and peer-to-peer ("P2P") networking, without the need for the user to change the software or processes that they currently use to retrieve, read, compose and send email, and without the use of a centralized control process or store and forward system. The invention includes: a central database and server that contains informs ion about which computers are currently using the solution; a proxy that provides message encryption and decryption services and manages the process of establishing a P2P connection between the sending and receiving systems. and;
a validation process that provides reasonable assurance that the sender and receiver of an email message has the authority to send and receive email messages using the email addresses contained in the header of the message.
a validation process that provides reasonable assurance that the sender and receiver of an email message has the authority to send and receive email messages using the email addresses contained in the header of the message.
Description
BACKGROUND OF THE INVENTION
Electronic mail (more commonly referred -to as "email") has introduced an extremely low cost means 15 far people to communicate with others around the world using the Internet, and has become the preferred means of electronic communications for individuals, businesses, and governments throughout the world. However email suffers from a distinct lack of privacy in that messages sent via email are not unlike postcards sent using the traditional postal service where anyone involved in the delivery of the postcard is able to read the message. Likewise an email message is typically in a format that can easily 20- ~be read ~by anyone with a connputer~ This problem is further exacerbated by the method that an email message is routed from the sender to the receiver. In many cases the route taken during message delivery can involve numerous computers and systems receiving and forwarding the message and even caching copies of the message while one system waits for another system to take delivery, thereby further exposing the contents of the message to anyone familiar with email delivery protocols.
25 In addition to a lack of privacy, the growing problem of address theft threatens the very integrity of email, as the current open standard that ; most email systems comply with makes it trivially easy for anyone to enter any email address that they want in the "From" field of the message header, making it appear that the message was sent by someone else. More and more "spammers"
(people who send Unsolicited Commercial Ernail ("UCE"); more commonly referred to as "spam") are now 'stealing' 30 and using the addresses of others in order to 'hide their real identity and shift. the blame for the spam that they send to sorrieone else who ends up being labeled a spammer, resulting in their email addresses being blocked by spare control software and: services. Governments, :businesses and even individuals are often the victims of damaging and disparaging email messages from people who impersonate others by stealing and using their email address:
35 Consequently; there is a need for an effective, low cost, and very easy to use method that provides a moderately secure means of sending and receiving email messages via the Internet, with reasonable assurance that the sender and receiver of an mail message has the authority to send and receive email to and from the email addresses that are contained in the header of the message:
DESCRIPTION OF -PRIOR ART . . ..
40 With respect to the secure delivery and receipt of email there are currently two commonly used approaches. The first is secure electronic mail ("secure entail") and the second is the use of Secure Socket Layer ("SSL") based deliveries using a website for uploading and downloading of email.
However, neither of these delivery miethods is fully satisfactory with respect to both ease of use and security.
45 Secure email works in the ' ame manner as unsecured email does; except that the email messages are encrypted: before they are sent: With unsecured email, the sender transmits his message to the recipient in an unencrypted state. Anyone who bas access to the systems that transmits the message will be able ,.
.. ,:
-_~ , , to'~reed 'e a a t~ m ss ge ' vvitli~ 'Iitfle or rio difficulty. With' secure 'eimail' "the sender° 'eiici ylils the 'message using an encryption key before it is sent to; the recipient. In this way if the message is intercepted while 50 in transit, it will be unreadable since (presumably) only the sender andlor receiver will have the key required to decrypt .the message. By limiting access to the decryption method and keys, the sender can limit who is able to read an encrypted message. By , encrypting the message before transmitting, the message is protected during transmission.
However, very few people actually use secure email as they find it too complicated to install and 55 configure, confusing to use, and only marginally useful due to the lack of adoption for any one secure email standard by other email users.
In addition to the problems that users experience when they try to use secure email is the fact that a secure email message is sent from the sender to the receiver using the same infrastructure as unsecured email, with mail being routed through unsecured and open systems that allows anyone to intercept the 60 message and with sufficient 'skills ~ and resources even decrypt the message using any number of techniques and cracking processes openly available on the Internet: Further, there is still a loss in privacy in that while the email raessage itself may be -encrypted, the message headers remain un-encrypted, revealing who the sender is; who they are sending email to, when and how often they send messages to various recipients, and what the subject is of the messages they do send.
65 The second common approach to sending and receiving secure email messages is the use of the Internet's Secure Socket Layer Protocol ("SSL") for the secure transmission of ernail messages. In this . approach, a..website .will..use its .digital certificate to authenticate itself to the sender using the SSL
protocol. Once the website is authenticated, a secure connection is set up'between'the sender's browser and the website: The message or document is then sent from the sender's browser to the website via the 70 secure connection and stored by the website until the recipient connects to the web site using SSL and downloads the message or document to their computer via the same type of secure connection.
This web based store and forward approach has many drawbacks: For example, SSL
only secures the delivery channels, the message typically remains in unencrypted state while it is temporarily stored by the website. If the website is attacked and a thirdparty is able to gain access to the site, then the third 75 party will be able to read the unencrypted email. In addition; if the website is untrustworthy or employees untrustworthy employees, a~ email stored on the site will be vulnerable.
To~ address t ~ ,. .
his weakness. there are SSL-based services that provide optiorial=password encryption of the email that is uploaded o them. However like secure email these systems are di~cult to use since they require the sender and receiver to agree on the password used to encrypt the message before they 8U can use the service.
To address the security risks of optional password protection of email there are other' SSL-based services that provide optional encryption of the documents using certificates.
These systems provide the best in email security, but are even more difficult to use because users must use an out of band process to obtain, manage-and exchange keys before they can exchange encrypted email.
85 Secure email and SSL-based delivery services have been available for a relatively long period of time, but neither has been widely adopted as they remain difficult to use ~d are non-transparent. Therefore, it is the objective of he present invention to provide a mvderatelyl secure email delivery system that: 1:) is completely transparent to the user; 2:) does not require the user to modify how they create, send, receive or read email; 3.) provides reasonable assurance that the sender and receiver have the authority 90 fo send and receive email with the ernail addresses used in the header of the message; 4.) does not require the user to configure or maintain-complex software, 5.) does not require a centralized control system to manage the process of sending or receiving secure ernail, and; 6.) does not handle or store any portion of email messages on third party computers.
SUMMARY OF THE INVENTION
95 In accordance .with the present invention,vthe'person who wishes ~o send or receive secure email installs an email security proxy (the 'proxy") '(102, 302) onto their computer. During the installation process the user validates the email addresses) they wish to use to send and receive email using an email based validation process (204) wherein the user enters the email addresses) they wish to validate into a validation web page on a website hosted by a Security Service, (201) and wherein the proxy (102, 302) 100 installation process generates and includes a unique GUID ("Globally Unique Identifier") that uniquely identifies the proxy, (102; 302) and wherein,a validation process (204) records the email addresses) provided by the user along with-the proxy GUID, and wherein he validation process (204) emails a randomly generated validation ID code to each address provided by the user, and wherein the user enters each randomly generated ID code for each email address that they submitted to the validation 105.,. . process..(2!04)aintoahe.proxy,(L.02;,.3Q2)..,eo~g that the user has the .authority to send and receive email messages with the addresses) they provided to the validation process.
(204) Once the user has entered a valid code into the proxy (102, 3Q2) for an email address, and the code has been validated by the Security Service, (200) the users validated email address is then added to he Address Validation Server (202) as an address that has been validated to send and receive secure email using the process 110 described herein.
Email messages are sent in a secure manner using public-key cryptography thereby requiring the user to generate a pair of encryption/decryption keys that will be used to automatically encrypt and decrypt email that is sent and received using the proxy (FU2, 302). Key generation is completed during software _4-_ ~~ -~ """",~~,~", _._.......
installation using a step-by: step wizard style process wherein- the user 'is instructed to provide a 115 randomized data set by simply moving their computer mouse in a-random fashion until a sufficiently large enough set of random characters are generated that can be used by the Eneryption/Decryption Module (105, 305) to generate the users unique public and private key pair.
Once the user has installed the proxy (102; -302j onto their computer, generated heir unique encryption/decryption key pair, and have validated at least one ~email address that can be used to send 120 and receive secure ernail, the user is then able to send and receive secure email using their preferred email software (101) to and from any other user who has installed the proxy (302) onto their computer and have validated their email address with the Security Service. (200).
The sender creates email messages using'their preferred email software. (101) When the user sends the ;._email message the prosy (102) intercepts (1) the outgoing message and parses aut:the email addresses 125 for each person that the message is destined to. The proxy (1Q2) then cheeks with the' Address Validation Server ("AVS") (202) to determine if any ' of the addresses that the email message is destined too have been validated with the Security Service: (200) Email that is destined to addresses that have not been validated with the Security Service (200) is sent to the addressees) in an unsecured manner using conventional email transmission protocols: Exnail that is destined to addresses that have 130 been validated with the Security: Service, (2U0) are encrypted by the sender's Encryption/Decryption Module ( 105) with the sender's personal encryption key and placed in the Outbound Message Queue "OlVIQ") (104) on the sender's computer. (1U0) The Peer-To-Peer ("P2P") Connection Module (106) then initiates the process of establishing a P2P connection between the sender and tha receiver for email that ~s,to be sent in a secure manner by using axi out of band rocess wherein a conventional .. , . ~.. "p".:~,..;., "~ .. ,~...:,..........v., I35 email message is generated by the sender's proxy (1U2) and sent to the receiver's proxy (302) using conventional email protocols: (2) The generated message includes a proxy ID
code in the subject line and the sender's symmetrically encrypted IP address. The proxy ID code in the subject line of the message tells the receiver's. proxy (302) that: 1) the entail message was sent by another proxy; 2.) the sending proxy ( 102) wants to establish a secure P2P connection between itself and the receiver's proxy, 140 (302) and; 3.) to decrypt and use the IP address o establish a P2P
connection between the sender's proxy (I02) and the receiver's proxy. (302) -5_ The receiver's P2P Connection lVlodule (106) decrypts the IP :address using it's built-in symmetrical key and establishes a secure connection between the sender's proxy ( 102) and the receiver's proxy (302). The sender's EncryptionlDecryption lVlodule (105) then decrypts all of the messages in the 145 send'er's OIVIQ (104) that are destined to. the receiver using the sender's personal decryption lcey. The sender's Encryption/Decryption Module (105) then re-encrypts each message using the receiver's public key and transmits each message to the .receiver's proxy (302) via the secure channel established between the sender's P2P Connection Module (1;06) and the receiver's P2P
Connection Module (306).
The receiver's Encryption/Deeryption Module (305) then decrypts each message using the receiver's 150 private decryption key and confirms to the sender's proxy ( 102) that it has successfixlty received each message. Once all messages have been transmitted, the receiver's P2P
Connection Module (306) terminates the secure connection between he sender and receiver. The sender's proxy (102) finishes by securely deleting the sent messages from the sender's OMQ, ( 104) and the sender's public encryption key. The receiver's proxy (302) finishes by forwarding (3) the decrypted email messages to the inbox 155 of the receivers preferred evil software: (301) BRIEF DESCRIPTION QF THE DRAWINGS
FIG: 1 is a schematic diagram showing ',the main components of the present invention;
FIG. 2 is a schematic diagram that shows the functionality of the present invention;
FIG. 3 is a functional block diagram of the preferred embodiment of the present invention;
I60 FIG. 4, 5 & 6 are- flow diagrams that describe the installation of the proxy software onto the users computer and the process used by the user to validate heir email address(es);
FIG. 7 is a flow diagram that describes the preferred embodiment of validating an email address, and;
FIG. 8 to 13 are flow diagrams that descn'bes how secure email is sent and received in accordance with preferred embodiment of the invention:
_6-165 DESCRIPTION OF TI3E PREFERRED EMBODIlI!IENT
Before turning to the figures; it will be useful to review the basic principles of cryptography. Cxenerally speaking there are two classes : of cryptographic algorit>~ms: symmetric key cryptography and asymmetric key cryptography. The keys themselves are typically large numbers generated from complex mathematical algorithms: These keys are used to encrypt and/or decrypt messages:
170 Symmetric key cryptography uses a single key to both encrypt and decrypt a message. A message encrypted with a symmetric key can only be decrypted by that same key. For example, if a sender encrypts. a message with a symmetric key and sends the encrypted message to a recipient, the recipient can decrypt the message only if he possesses the same key that the sender used to encrypt the message.
Asymmetric key encryption, more commonly called public-keys encryption, involves a pair of keys - a 175 public key and a private key. Once a user has generated a key pair, the user typically keeps the private key secret but publishes the corresponding public key. The public key and the private key are mathematically related so that one key can decrypt a message encrypted by the other key. However, the mathematical relationship between the keys is su~ciently complex that it is computationally infeasible to derive one key given the other., Thus, if a sender wants to send a message to a recipient in a manner 180 such that only the recipient can read the message, the sender can encrypt the message with the recipient's public key. Since only the recipieixt's private key can decrypt the message, the sender can be assured that only the recipient can read the message; assuming that the recipient is the only one with access to the private key.
Turning no'w t6 the figures; FIG. 1 is a schematic diagraiii representing the three' main components of 185 the fully functional; moderately secure; non-centralized email transmission and address validation process, including the sender (I00) the email Security Service (200) and the receiver (300). The sender ( 100) wants to send email in a secure and, private manner and wants reasonable assurance that the person who receives the message is the person the email was sent to. The receiver (300) wants reasonable assurance that the email they receive has not been read by anyone else and that the message 190 is from the owner of the email address that the message was sent from. The email Security Service (200) provides validation of email ;addresses used by the sender (100) and receiver (300), and information about what users have a validated email address:
It should be noted that the role of the sender ( 100) and receiver (300) may be reversed. In addition senders and receivers could represent individuals or other entities such as a business, Internet': Service 195 Providers ("ISP") or Exnail Service Providers ("ESP"). It should also be noted that the sending or receiving systems may be a Personal Computer ("PC") or a server used to queue, send, receive and hold email. It should also be noted that there may be one-to-one, one-to-many and many-to-one relationships between sending and receiving systems.
FIG: 2 is schematic diagram that provides ~ overview of how email addresses are validated and how 200 email is sent using a secure P2P connection and public key cryptography.
Lets begin with the sender (100) who wishes to send an email message to the receiver.' (300) The sender composes and sends email messages in the usual manner using their preferred email software. (10i) The sender's proxy . , . :( 102) .intercepts. the outgoing .email message and parses :,out all of the exnail addresses in the To, CC;
and BCC fields and submits a: query via the Internet (4; 8) for each ema;il address to the Addresses 205 Validation Server ("AVS") (202) to determine which addresses have been validated by the address owner using the email validation process ,(204). The AVS (202) sends a reply (9, 5) to the sender's proxy (102) that includes all email addresses that have been validated. The sender's proxy (102) prepares and sends a conventional email message via an ESP (4, 7, 6, 12) to each validated email address that includes the sender's Symmetrically encrypted IP address. The receiver's proxy (302) 210 receives the email message and decrypts the IP address arzd uses the IP
address to establish a secure, bi-directional P2P connection between the sender's proxy (102) and the receiver's proxy (302). ( 13; 5, 4, 12) Once a direct connection is established between the sender's proxy ( 102) and the receiver's proxy, (302) the receiver's proxy (302) sends the receiver's public key to the sender via the secure channel.
.. ~..: . , _ ... w (1~,.=s~ Th$: sender's.~roxy.(502) then.uses«the receiver's public~key to enc- tall-,of the messa es~~
rfP g 215 destined to the receiver: The encrypted email messages are then sent to the receiver via the secured channel. (4, 12) The receiver's proxy (302) decrypts the received messages) using the receiver's private decryption key and conf~rrns the successful receipt and decryption of the messages to the sender's proxy. (102) (13, 5) The receiver's proxy (302) then closes the P2P
connection between the sender and receiver, ( 13, 5; 4; 12). arid forwards the decrypted messages to the receiver's preferred 220 email software. (301) Email addresses are validated using an email based validation process wherein the user validates each email address that they wish to send secure eW ail with by connecting (4, 11) to the email security service's {200) email validation web page (201) and entering the ernail address they wish to have validated. In addition to the email address entered by the user,;the users proxy (102) also provides it's 225 encrypted GUID (which is, generated v~hen the user installs the proxy software onto their computer) to the email validation process (204) via the validation webpage. (201) The email validation process then validates the email address by generating a validation code and emailing it using conventional email protocols to the email address that was entered into the email validation webpage. (10; 7, 6, 5) When the user receives the email message they are instructed to enter the code into their proxy ( 102) 230 whereupon the proxy (102) sends the entered code and it's GUID to the email validation process (204) {4, 14) to confirm the validity of the code and validate that the user has the authority to send and receive email messages using the email address.: The process concludes when the email validation process (204) sends (15} the validated email address to the AVS. (202) , FIG: 3 is'a functional block diagrarri of the preferred embodiment of the system as shown in FIG. 1 and 235 2. In this embodiment each of the Sending ( 100) and Receiving (300) systems includes a Configuration Module (103, 303); Outbound Message Queue ("OMQ°') (104;.304), EncryptionlDeeryption Module ( 105, 305), and a Peer-To-Peer Connection Module ( l Ob, 306), all of which may communicate with each other within the proxy software. In the preferred embodiment each of the modules are implemented as software, but can also be implemented as hardware and/or firmware. Examples of 240 sending and receiving systems ( 100, 300) may include; but are not limited to desktop computers, portable computers, servers, PpAs, wireless devices and other digital devices.
The Email Security Service (200) includes a Security Service Website (201), Email Validation Module (204), Proxy Registration Module (205), Administration Module 202), Validation Database 203 and ...,~F ,....,::. . =,. .. ~ , .,( ~ ;F4~:~ .., , , ,. , ..,~ y, ,. , Address Validation Server ("AVS") (202). All of which may communicate with each other. In the 245 preferred embodiment, each of the modules are implemented as software, but can also be implemented as hardware and/or firmware. An example of an implementation of an Email Security Service (200) would include server software running on LTNI~, Linux, Windows NT/20UU/XP or Sun Solaris systems.
The system. outlined in Fig. 3 generally operates in a manner described by the flow charts illustrated in 250 Fig. 4 to Fig 13, which will be described below.
Turning now to Fig 4., the process begins with a user vvho wants to send and receive secure email.
They may learn about this new email security system from friends and acquaintances that have already installed the proxy onto their personal computers, or from an email message asking the user ao install the proxy so that they, can receive a secure message from a user that already has the proxy installed. As 255 a result, they decide that they want to install the proxy and download the software from any one of the many software distribution hubs on the Internet, or directly from the email Security Service's own website. ' During installation a GUID is generated (404) that uniquely identifies the proxy (1o2, 302) installation.
The process embeds the encrypted GUID into a URL ("UniformResource Locator") (408), launches 260 the users browser with the URL direeting the user to an email vaiidation webpage (406) hosted by the ._ . _.. . ~ _ ._ _ Seourityn Servace: _(200)_. The. user.enters..the.:email address that:.they wish to. validate .into the validation.
webpage and submits the page to the Security Service. {200): (420) The users email address and the encrypted GUID are submitted to the address validation module (204) and a validation request confirmationrnessage is displayed in the users browser,telling the user to expect an email message with 265 a validation code for the email: address that they provided. (412) The user is then provided with the option to validate additional exnaal addresses. (414) Jumping forward to Fig:
7 now, the Email Validation module decrypts the QUID (505) and randomly generates an email address validation code.
(510) The module saves the validation code, email address and GUID to the validation database (203).
(515) The module generates and sends an email message to the email address that was submitted for 270 validation that includes the validation code and instructions for installing the code into the proxy. ( 102, 302) (520) If the validation email message bounces (returned as an invalid address) (525), then the . . ;. ;,:,,. p~a~s~>updates- he entry=in-the~validation-.database(203).ao.:indieaxe~that the emarl address was invalid. _, (530) Continuing now with Fig. 5 the install process continues with the user registering their software with 275 the Security Service. (200) (418) Once the proxy ( 102; 3U2) has been installed and registered,' (420) the process continues with the user being provided with the option (422) 'to configure the software using a step-by-step wizard style configuration process, (424) or an advanced;
dialogue based configuration process: (432) During the configuration process the user is asked if they base received their email address validation eode(s). (426) If not, they are told that while they can complete the installation, they 280 will not be able to send or receive secure email messages until hey enter at least one validation code.
10_ (434) If they have received their validation cot~e(s) they are instructed to enter the validation codes into the proxy. (102, 302) (428) The proxy (102, 302) in turn sends each entered validation code along with the proxy's GUID to the email Security Serviee. (2UU) (430) The email Validation Module (204) submits a query to the validation database (2U3) to determine if the submitted code and: proxy GUID
285 matches the information contained in the database: (436) If there is a matching code and corresponding matching GLJID in the validation database (203); (438; 440) then the Validation Module adds the validated email address to the AVS (202) (442) and ends a validation-accepted message to the proxy (102, 302) (444) whereupon the proxy (102, 302) enables the validated email address allowing authorized users to send and receive secure: email messages using the address.
(446, 448) If there is no 290 match for the submitted code and/or GUIDE the Validation Module (204) notifies ,the proxy ( 102, 302) that the entered codes) were invalid and the proxy (1U2, 302) advises the user that the codes they .. ~ h v."li . _._ added vvilt riot Work: ~' (450, 52) The user is t en o~'ered the ;option to try' and a date ~ariotlier einail address. (454) Moving now to Fig. 8 we will now describe how email is sent and received in a secure manner using 295 the preferred embodiment of~fhe invention. The user (the "sender")who wishes to send a secure email message prepares and sends their message using their preferred email software.
(602) If the-proxy ( 102) has been enabled to send secure email, (604) it will monitor all outbound email traffic intercepting each outbound message and parsing out all of the email addresses contained in the From, To, CC, and BCC
fields. (606) The proxy (102) then determines if the email address in the From field has been validated:
300 (608) If it has not, then the sender is asked if they want to validate the email address so that the message can be sent in. a secure manner. (61:8) If the ender does not wish to validate the email address, :,, ~. ..
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vL _ :_~~.:x~., f thenal~messa evis=~s~nt:.x~,.all~,:ofahe~~addr~essees~.usin :corrventlanal-email; rot~eols:. 6~6E~~ f- e< t, :,.-,,;~
g g p ( ) I th sender wants to validate the email address so that the message is sent in a secure manner; then the proxy ( 102) encrypts the message with the sender's personal encryption key; (to protect the confidentiality of the 305 message while the proxy (102) validates :the sender's email address and prepares the message for transmission) and stores the encrypted message on the sender's computer. (100) At the same time the proxy (102) creates an entry for each addressee that the message is destined to in the OMQ. (104) (621) The proxy (102) then launches the email validation process and the sender completes the validation process as previously described. (622) _11_ 310 If the email address in the From :field has been validated then the proxy ( 102) encrypts the message with the sender's personal encryption key (to protect the confidentiality of the message while the proxy ( 102) prepares the message , for transmission) and stores he encrypted message on the sender's computer: ( 100) At the same time the proxy ( 102) creates an entry for each addressee that the message is destined to in the OMQ. ( L04) (610) 315 The proxy (102) then sends a request to the AVS (202) to determine the validation status of the addresses in the To, CC and BCC fields. (612) If there are any addresses that have not been validated, (614) and if the sender has configured the proxy (102) to automatically send email messages to un-validated addresses in an unsecured manner; (624) hen the proxy (102) decrypts a copy of the message using the sender's personal decryption key (623) and sends the message to all non-validated addressees .. .. .. : 320 . . using. con~rentional .:,emait ..piotoeols.: (616) The .
proxy (102). then :.updates . each ,address in the . QMQ
( 104) to indicate that what'addresses the message was sent to using conventional email. (615) If the sender has configured the proxy (102) to notify them when there are messages destined to. non-validated addressees; then the proxy ( 102) displays a message, to the sender advising them that there are messages for non-validated addresses in the OMQ. (104) (638) The sender reviews the addressees in 325 he OMQ (104) and flags messages that may be sent in an unsecured manner.
(64.0) The proxy (102) in turn regularly monitors the OlVIQ ( 104) for messages that have been reviewed by the sender. If the sender has flagged messages that can be sent in an unsecured manner, ,(642) then the proxy ( 102) decrypts the message using the sender's personal decryption key (630) and sends the message to all of the flagged addressees using conventional email protocols: (632) < r _ ;,.~"" .
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r~ 4~.
330 ~ 'If the sender ~ lia's fla '~ ed~ ad ~ s th t u~ t ~ s t ' gg dyes es a m s be en m' a secure niaiuier,~ (~44~ ; then the proxy ( 102) uses a pre-defined message template that was created by the sender when they installed the proxy ( 102) software onto their computer to generate and send a conventional email message that advises the receiver that the sender wants to send them a secure xriessage and in order to receive the message they must install and configure the proxy (302) and validate their email address.
(646, 648) The proxy (102) 335 then begins to regularly monitor the AVS (202) for the receiver's validated email address. (649) If the message sent to the receiver bounces, (650) the proxy ( 102) updates the entry in the OMQ ( 104) to indicate that the receivers email address is invalid and discontinues monitoring the AVS (2Q2) for the receiver's address: (660) If the sender has specified that the message should be sent in an unsecured manner and if the receiver 340 has not responded to.the proxy installation and validation, reqpest after a preset period of time, (654) then the proxy (102) will discontinue monitoring the pMQ (104) for the receivers validated ernail address, (662) decrypt (663) and send the message to the receiver using conventional email protocols, (664) and updates the OMQ (104) to indicate that the receiver never validated their email address and that the message was sent in an unsecured manner using conventional email.
(665) If the sender 345 specified than the rriessage must be sent in a secure manner, then the proxy ( 102) simply continues to monitor the AVS (202) for an indefinite period of time for the receiver to validate their email address.
(658) If the receiver's email address is added to the AVS (202)' indicating that the receiver has installed and .... eonfigured,the:groxyr,(3.02) hen the ender's proxy.(102) dueries the operating ystem for it's currently .
350 assigned IP address:' (626) The IP address is ,then encrypted by the proxy ,(102) using a built in symmetrical encryption algorithm and encryption key. (628) The proxy (102) then generates a conventional email message (666) that includes: 1:) a proxy ID code in the subject line that is used by the receivers proxy (302) to intercept messages intended- for the proxy (302) (668); 2.) The sender's symmetrically encrypted IP address, and (670); 3:) a human readable message in the body of the email 355 that explains what the emaii is about in case the receivers proxy (302) fails to intercept the message, or in case the receiver has- removed the proxy (302) from their computer. (672) The proxy ( 102) then sends fhe email message to the receiver's proxy (302) using conventional email protocols: (674);
The receiver's proxy (302) monitors each incoming email message for an ID code in the Su>;ject field that tells the proxy (302) that the message was sent by anther proxy. (676) If the subject field contains 360 a proxy ID code, then the receiver's proxy (302) intercepts the message, preventing it from being forwarded to the receivers normal email software. (680) The receiver's proxy (302) then parses the message and decrypts the IP address using its built in symmetrical decryption algoritlun and decryption key. (683) The receiver's proxy (302) then attempts to establish a secure P2P
connection with the sender's proxy (102) using the IP address provided by the sender's proxy.
(i02) (684) If the receiver is 365 unable to establish a secure connection with the sender's proxy, (102) (686) the receiver's, proxy (302) composes 'and sends a conventional email message .that contains a proxy 'ID
code in the subject line, asking the sender's proxy (102) tore-send it's current IP address. (694) This process will be repeated until the receiver's proxy (302) is able to establish a secure connection with the sender's proxy; (102) _13_ or until the number of iterations reaches a value established by the sender whereupon the ender's 370 proxy (102) will either send the message in an unsecured manner, or flags the message in the ender's OMQ ( 104) as not sent due to P2P connection failure. Once a secure P2P
connection has been established between the receiver's proxy (3U2) and the sender's proxy, ( 102) the receiver's proxy (302) transmits the r~eiver's current public encryption key to the sender's proxy (102) (688) : and the sender's proxy ( 102) confirms receipt of the receiver's -public key. (690) The sender's proxy ( 102) then 375 decrypts all email messages that are destined to the r~eiver using the sender's private. decryption key, (692) and then re-encrypts each message destined to the receiver with the receiver's public encryption key. (696) The sender's proxy (102) then transmits all encrypted messages o the receiver's proxy (302) via the secure P2P channel: (698) The receiver's proxy (302) then decrypts each received message using the receiver's private decryption key (740) and confirms the successful delivery of each message ..,~..~. ..~.... , .
380-_ .:_;~o...he~.>:. .d s . , t sen er -proxy. ('102) (704) Tfa message~vi!as notauccessf"'ully recei~ed~and neeiypted;'(702) then the receiver's proxy (3U2) will send a request to the sender's proxy (102) via the secure P2P channel; to re-transmit the message. (710) Once all of the messages have been successfully transmitted and decrypted, the receiver's proxy (302) closes the P2P connection (712) and pass all of the decrypted email messages on to the receivers preferred email software. (714) Once the P2P connection has been 385 closed-by the receiver's proxy (302), the sender's proky (102) updates each-entry in the Q1VIQ (104) indicating what messages were successfully sent in a secure manner to the receiver. (706) The sender's proxy (102) then securely deletes the receiver's public keyfrom the sender's computer. (?08)
Electronic mail (more commonly referred -to as "email") has introduced an extremely low cost means 15 far people to communicate with others around the world using the Internet, and has become the preferred means of electronic communications for individuals, businesses, and governments throughout the world. However email suffers from a distinct lack of privacy in that messages sent via email are not unlike postcards sent using the traditional postal service where anyone involved in the delivery of the postcard is able to read the message. Likewise an email message is typically in a format that can easily 20- ~be read ~by anyone with a connputer~ This problem is further exacerbated by the method that an email message is routed from the sender to the receiver. In many cases the route taken during message delivery can involve numerous computers and systems receiving and forwarding the message and even caching copies of the message while one system waits for another system to take delivery, thereby further exposing the contents of the message to anyone familiar with email delivery protocols.
25 In addition to a lack of privacy, the growing problem of address theft threatens the very integrity of email, as the current open standard that ; most email systems comply with makes it trivially easy for anyone to enter any email address that they want in the "From" field of the message header, making it appear that the message was sent by someone else. More and more "spammers"
(people who send Unsolicited Commercial Ernail ("UCE"); more commonly referred to as "spam") are now 'stealing' 30 and using the addresses of others in order to 'hide their real identity and shift. the blame for the spam that they send to sorrieone else who ends up being labeled a spammer, resulting in their email addresses being blocked by spare control software and: services. Governments, :businesses and even individuals are often the victims of damaging and disparaging email messages from people who impersonate others by stealing and using their email address:
35 Consequently; there is a need for an effective, low cost, and very easy to use method that provides a moderately secure means of sending and receiving email messages via the Internet, with reasonable assurance that the sender and receiver of an mail message has the authority to send and receive email to and from the email addresses that are contained in the header of the message:
DESCRIPTION OF -PRIOR ART . . ..
40 With respect to the secure delivery and receipt of email there are currently two commonly used approaches. The first is secure electronic mail ("secure entail") and the second is the use of Secure Socket Layer ("SSL") based deliveries using a website for uploading and downloading of email.
However, neither of these delivery miethods is fully satisfactory with respect to both ease of use and security.
45 Secure email works in the ' ame manner as unsecured email does; except that the email messages are encrypted: before they are sent: With unsecured email, the sender transmits his message to the recipient in an unencrypted state. Anyone who bas access to the systems that transmits the message will be able ,.
.. ,:
-_~ , , to'~reed 'e a a t~ m ss ge ' vvitli~ 'Iitfle or rio difficulty. With' secure 'eimail' "the sender° 'eiici ylils the 'message using an encryption key before it is sent to; the recipient. In this way if the message is intercepted while 50 in transit, it will be unreadable since (presumably) only the sender andlor receiver will have the key required to decrypt .the message. By limiting access to the decryption method and keys, the sender can limit who is able to read an encrypted message. By , encrypting the message before transmitting, the message is protected during transmission.
However, very few people actually use secure email as they find it too complicated to install and 55 configure, confusing to use, and only marginally useful due to the lack of adoption for any one secure email standard by other email users.
In addition to the problems that users experience when they try to use secure email is the fact that a secure email message is sent from the sender to the receiver using the same infrastructure as unsecured email, with mail being routed through unsecured and open systems that allows anyone to intercept the 60 message and with sufficient 'skills ~ and resources even decrypt the message using any number of techniques and cracking processes openly available on the Internet: Further, there is still a loss in privacy in that while the email raessage itself may be -encrypted, the message headers remain un-encrypted, revealing who the sender is; who they are sending email to, when and how often they send messages to various recipients, and what the subject is of the messages they do send.
65 The second common approach to sending and receiving secure email messages is the use of the Internet's Secure Socket Layer Protocol ("SSL") for the secure transmission of ernail messages. In this . approach, a..website .will..use its .digital certificate to authenticate itself to the sender using the SSL
protocol. Once the website is authenticated, a secure connection is set up'between'the sender's browser and the website: The message or document is then sent from the sender's browser to the website via the 70 secure connection and stored by the website until the recipient connects to the web site using SSL and downloads the message or document to their computer via the same type of secure connection.
This web based store and forward approach has many drawbacks: For example, SSL
only secures the delivery channels, the message typically remains in unencrypted state while it is temporarily stored by the website. If the website is attacked and a thirdparty is able to gain access to the site, then the third 75 party will be able to read the unencrypted email. In addition; if the website is untrustworthy or employees untrustworthy employees, a~ email stored on the site will be vulnerable.
To~ address t ~ ,. .
his weakness. there are SSL-based services that provide optiorial=password encryption of the email that is uploaded o them. However like secure email these systems are di~cult to use since they require the sender and receiver to agree on the password used to encrypt the message before they 8U can use the service.
To address the security risks of optional password protection of email there are other' SSL-based services that provide optional encryption of the documents using certificates.
These systems provide the best in email security, but are even more difficult to use because users must use an out of band process to obtain, manage-and exchange keys before they can exchange encrypted email.
85 Secure email and SSL-based delivery services have been available for a relatively long period of time, but neither has been widely adopted as they remain difficult to use ~d are non-transparent. Therefore, it is the objective of he present invention to provide a mvderatelyl secure email delivery system that: 1:) is completely transparent to the user; 2:) does not require the user to modify how they create, send, receive or read email; 3.) provides reasonable assurance that the sender and receiver have the authority 90 fo send and receive email with the ernail addresses used in the header of the message; 4.) does not require the user to configure or maintain-complex software, 5.) does not require a centralized control system to manage the process of sending or receiving secure ernail, and; 6.) does not handle or store any portion of email messages on third party computers.
SUMMARY OF THE INVENTION
95 In accordance .with the present invention,vthe'person who wishes ~o send or receive secure email installs an email security proxy (the 'proxy") '(102, 302) onto their computer. During the installation process the user validates the email addresses) they wish to use to send and receive email using an email based validation process (204) wherein the user enters the email addresses) they wish to validate into a validation web page on a website hosted by a Security Service, (201) and wherein the proxy (102, 302) 100 installation process generates and includes a unique GUID ("Globally Unique Identifier") that uniquely identifies the proxy, (102; 302) and wherein,a validation process (204) records the email addresses) provided by the user along with-the proxy GUID, and wherein he validation process (204) emails a randomly generated validation ID code to each address provided by the user, and wherein the user enters each randomly generated ID code for each email address that they submitted to the validation 105.,. . process..(2!04)aintoahe.proxy,(L.02;,.3Q2)..,eo~g that the user has the .authority to send and receive email messages with the addresses) they provided to the validation process.
(204) Once the user has entered a valid code into the proxy (102, 3Q2) for an email address, and the code has been validated by the Security Service, (200) the users validated email address is then added to he Address Validation Server (202) as an address that has been validated to send and receive secure email using the process 110 described herein.
Email messages are sent in a secure manner using public-key cryptography thereby requiring the user to generate a pair of encryption/decryption keys that will be used to automatically encrypt and decrypt email that is sent and received using the proxy (FU2, 302). Key generation is completed during software _4-_ ~~ -~ """",~~,~", _._.......
installation using a step-by: step wizard style process wherein- the user 'is instructed to provide a 115 randomized data set by simply moving their computer mouse in a-random fashion until a sufficiently large enough set of random characters are generated that can be used by the Eneryption/Decryption Module (105, 305) to generate the users unique public and private key pair.
Once the user has installed the proxy (102; -302j onto their computer, generated heir unique encryption/decryption key pair, and have validated at least one ~email address that can be used to send 120 and receive secure ernail, the user is then able to send and receive secure email using their preferred email software (101) to and from any other user who has installed the proxy (302) onto their computer and have validated their email address with the Security Service. (200).
The sender creates email messages using'their preferred email software. (101) When the user sends the ;._email message the prosy (102) intercepts (1) the outgoing message and parses aut:the email addresses 125 for each person that the message is destined to. The proxy (1Q2) then cheeks with the' Address Validation Server ("AVS") (202) to determine if any ' of the addresses that the email message is destined too have been validated with the Security Service: (200) Email that is destined to addresses that have not been validated with the Security Service (200) is sent to the addressees) in an unsecured manner using conventional email transmission protocols: Exnail that is destined to addresses that have 130 been validated with the Security: Service, (2U0) are encrypted by the sender's Encryption/Decryption Module ( 105) with the sender's personal encryption key and placed in the Outbound Message Queue "OlVIQ") (104) on the sender's computer. (1U0) The Peer-To-Peer ("P2P") Connection Module (106) then initiates the process of establishing a P2P connection between the sender and tha receiver for email that ~s,to be sent in a secure manner by using axi out of band rocess wherein a conventional .. , . ~.. "p".:~,..;., "~ .. ,~...:,..........v., I35 email message is generated by the sender's proxy (1U2) and sent to the receiver's proxy (302) using conventional email protocols: (2) The generated message includes a proxy ID
code in the subject line and the sender's symmetrically encrypted IP address. The proxy ID code in the subject line of the message tells the receiver's. proxy (302) that: 1) the entail message was sent by another proxy; 2.) the sending proxy ( 102) wants to establish a secure P2P connection between itself and the receiver's proxy, 140 (302) and; 3.) to decrypt and use the IP address o establish a P2P
connection between the sender's proxy (I02) and the receiver's proxy. (302) -5_ The receiver's P2P Connection lVlodule (106) decrypts the IP :address using it's built-in symmetrical key and establishes a secure connection between the sender's proxy ( 102) and the receiver's proxy (302). The sender's EncryptionlDecryption lVlodule (105) then decrypts all of the messages in the 145 send'er's OIVIQ (104) that are destined to. the receiver using the sender's personal decryption lcey. The sender's Encryption/Decryption Module (105) then re-encrypts each message using the receiver's public key and transmits each message to the .receiver's proxy (302) via the secure channel established between the sender's P2P Connection Module (1;06) and the receiver's P2P
Connection Module (306).
The receiver's Encryption/Deeryption Module (305) then decrypts each message using the receiver's 150 private decryption key and confirms to the sender's proxy ( 102) that it has successfixlty received each message. Once all messages have been transmitted, the receiver's P2P
Connection Module (306) terminates the secure connection between he sender and receiver. The sender's proxy (102) finishes by securely deleting the sent messages from the sender's OMQ, ( 104) and the sender's public encryption key. The receiver's proxy (302) finishes by forwarding (3) the decrypted email messages to the inbox 155 of the receivers preferred evil software: (301) BRIEF DESCRIPTION QF THE DRAWINGS
FIG: 1 is a schematic diagram showing ',the main components of the present invention;
FIG. 2 is a schematic diagram that shows the functionality of the present invention;
FIG. 3 is a functional block diagram of the preferred embodiment of the present invention;
I60 FIG. 4, 5 & 6 are- flow diagrams that describe the installation of the proxy software onto the users computer and the process used by the user to validate heir email address(es);
FIG. 7 is a flow diagram that describes the preferred embodiment of validating an email address, and;
FIG. 8 to 13 are flow diagrams that descn'bes how secure email is sent and received in accordance with preferred embodiment of the invention:
_6-165 DESCRIPTION OF TI3E PREFERRED EMBODIlI!IENT
Before turning to the figures; it will be useful to review the basic principles of cryptography. Cxenerally speaking there are two classes : of cryptographic algorit>~ms: symmetric key cryptography and asymmetric key cryptography. The keys themselves are typically large numbers generated from complex mathematical algorithms: These keys are used to encrypt and/or decrypt messages:
170 Symmetric key cryptography uses a single key to both encrypt and decrypt a message. A message encrypted with a symmetric key can only be decrypted by that same key. For example, if a sender encrypts. a message with a symmetric key and sends the encrypted message to a recipient, the recipient can decrypt the message only if he possesses the same key that the sender used to encrypt the message.
Asymmetric key encryption, more commonly called public-keys encryption, involves a pair of keys - a 175 public key and a private key. Once a user has generated a key pair, the user typically keeps the private key secret but publishes the corresponding public key. The public key and the private key are mathematically related so that one key can decrypt a message encrypted by the other key. However, the mathematical relationship between the keys is su~ciently complex that it is computationally infeasible to derive one key given the other., Thus, if a sender wants to send a message to a recipient in a manner 180 such that only the recipient can read the message, the sender can encrypt the message with the recipient's public key. Since only the recipieixt's private key can decrypt the message, the sender can be assured that only the recipient can read the message; assuming that the recipient is the only one with access to the private key.
Turning no'w t6 the figures; FIG. 1 is a schematic diagraiii representing the three' main components of 185 the fully functional; moderately secure; non-centralized email transmission and address validation process, including the sender (I00) the email Security Service (200) and the receiver (300). The sender ( 100) wants to send email in a secure and, private manner and wants reasonable assurance that the person who receives the message is the person the email was sent to. The receiver (300) wants reasonable assurance that the email they receive has not been read by anyone else and that the message 190 is from the owner of the email address that the message was sent from. The email Security Service (200) provides validation of email ;addresses used by the sender (100) and receiver (300), and information about what users have a validated email address:
It should be noted that the role of the sender ( 100) and receiver (300) may be reversed. In addition senders and receivers could represent individuals or other entities such as a business, Internet': Service 195 Providers ("ISP") or Exnail Service Providers ("ESP"). It should also be noted that the sending or receiving systems may be a Personal Computer ("PC") or a server used to queue, send, receive and hold email. It should also be noted that there may be one-to-one, one-to-many and many-to-one relationships between sending and receiving systems.
FIG: 2 is schematic diagram that provides ~ overview of how email addresses are validated and how 200 email is sent using a secure P2P connection and public key cryptography.
Lets begin with the sender (100) who wishes to send an email message to the receiver.' (300) The sender composes and sends email messages in the usual manner using their preferred email software. (10i) The sender's proxy . , . :( 102) .intercepts. the outgoing .email message and parses :,out all of the exnail addresses in the To, CC;
and BCC fields and submits a: query via the Internet (4; 8) for each ema;il address to the Addresses 205 Validation Server ("AVS") (202) to determine which addresses have been validated by the address owner using the email validation process ,(204). The AVS (202) sends a reply (9, 5) to the sender's proxy (102) that includes all email addresses that have been validated. The sender's proxy (102) prepares and sends a conventional email message via an ESP (4, 7, 6, 12) to each validated email address that includes the sender's Symmetrically encrypted IP address. The receiver's proxy (302) 210 receives the email message and decrypts the IP address arzd uses the IP
address to establish a secure, bi-directional P2P connection between the sender's proxy (102) and the receiver's proxy (302). ( 13; 5, 4, 12) Once a direct connection is established between the sender's proxy ( 102) and the receiver's proxy, (302) the receiver's proxy (302) sends the receiver's public key to the sender via the secure channel.
.. ~..: . , _ ... w (1~,.=s~ Th$: sender's.~roxy.(502) then.uses«the receiver's public~key to enc- tall-,of the messa es~~
rfP g 215 destined to the receiver: The encrypted email messages are then sent to the receiver via the secured channel. (4, 12) The receiver's proxy (302) decrypts the received messages) using the receiver's private decryption key and conf~rrns the successful receipt and decryption of the messages to the sender's proxy. (102) (13, 5) The receiver's proxy (302) then closes the P2P
connection between the sender and receiver, ( 13, 5; 4; 12). arid forwards the decrypted messages to the receiver's preferred 220 email software. (301) Email addresses are validated using an email based validation process wherein the user validates each email address that they wish to send secure eW ail with by connecting (4, 11) to the email security service's {200) email validation web page (201) and entering the ernail address they wish to have validated. In addition to the email address entered by the user,;the users proxy (102) also provides it's 225 encrypted GUID (which is, generated v~hen the user installs the proxy software onto their computer) to the email validation process (204) via the validation webpage. (201) The email validation process then validates the email address by generating a validation code and emailing it using conventional email protocols to the email address that was entered into the email validation webpage. (10; 7, 6, 5) When the user receives the email message they are instructed to enter the code into their proxy ( 102) 230 whereupon the proxy (102) sends the entered code and it's GUID to the email validation process (204) {4, 14) to confirm the validity of the code and validate that the user has the authority to send and receive email messages using the email address.: The process concludes when the email validation process (204) sends (15} the validated email address to the AVS. (202) , FIG: 3 is'a functional block diagrarri of the preferred embodiment of the system as shown in FIG. 1 and 235 2. In this embodiment each of the Sending ( 100) and Receiving (300) systems includes a Configuration Module (103, 303); Outbound Message Queue ("OMQ°') (104;.304), EncryptionlDeeryption Module ( 105, 305), and a Peer-To-Peer Connection Module ( l Ob, 306), all of which may communicate with each other within the proxy software. In the preferred embodiment each of the modules are implemented as software, but can also be implemented as hardware and/or firmware. Examples of 240 sending and receiving systems ( 100, 300) may include; but are not limited to desktop computers, portable computers, servers, PpAs, wireless devices and other digital devices.
The Email Security Service (200) includes a Security Service Website (201), Email Validation Module (204), Proxy Registration Module (205), Administration Module 202), Validation Database 203 and ...,~F ,....,::. . =,. .. ~ , .,( ~ ;F4~:~ .., , , ,. , ..,~ y, ,. , Address Validation Server ("AVS") (202). All of which may communicate with each other. In the 245 preferred embodiment, each of the modules are implemented as software, but can also be implemented as hardware and/or firmware. An example of an implementation of an Email Security Service (200) would include server software running on LTNI~, Linux, Windows NT/20UU/XP or Sun Solaris systems.
The system. outlined in Fig. 3 generally operates in a manner described by the flow charts illustrated in 250 Fig. 4 to Fig 13, which will be described below.
Turning now to Fig 4., the process begins with a user vvho wants to send and receive secure email.
They may learn about this new email security system from friends and acquaintances that have already installed the proxy onto their personal computers, or from an email message asking the user ao install the proxy so that they, can receive a secure message from a user that already has the proxy installed. As 255 a result, they decide that they want to install the proxy and download the software from any one of the many software distribution hubs on the Internet, or directly from the email Security Service's own website. ' During installation a GUID is generated (404) that uniquely identifies the proxy (1o2, 302) installation.
The process embeds the encrypted GUID into a URL ("UniformResource Locator") (408), launches 260 the users browser with the URL direeting the user to an email vaiidation webpage (406) hosted by the ._ . _.. . ~ _ ._ _ Seourityn Servace: _(200)_. The. user.enters..the.:email address that:.they wish to. validate .into the validation.
webpage and submits the page to the Security Service. {200): (420) The users email address and the encrypted GUID are submitted to the address validation module (204) and a validation request confirmationrnessage is displayed in the users browser,telling the user to expect an email message with 265 a validation code for the email: address that they provided. (412) The user is then provided with the option to validate additional exnaal addresses. (414) Jumping forward to Fig:
7 now, the Email Validation module decrypts the QUID (505) and randomly generates an email address validation code.
(510) The module saves the validation code, email address and GUID to the validation database (203).
(515) The module generates and sends an email message to the email address that was submitted for 270 validation that includes the validation code and instructions for installing the code into the proxy. ( 102, 302) (520) If the validation email message bounces (returned as an invalid address) (525), then the . . ;. ;,:,,. p~a~s~>updates- he entry=in-the~validation-.database(203).ao.:indieaxe~that the emarl address was invalid. _, (530) Continuing now with Fig. 5 the install process continues with the user registering their software with 275 the Security Service. (200) (418) Once the proxy ( 102; 3U2) has been installed and registered,' (420) the process continues with the user being provided with the option (422) 'to configure the software using a step-by-step wizard style configuration process, (424) or an advanced;
dialogue based configuration process: (432) During the configuration process the user is asked if they base received their email address validation eode(s). (426) If not, they are told that while they can complete the installation, they 280 will not be able to send or receive secure email messages until hey enter at least one validation code.
10_ (434) If they have received their validation cot~e(s) they are instructed to enter the validation codes into the proxy. (102, 302) (428) The proxy (102, 302) in turn sends each entered validation code along with the proxy's GUID to the email Security Serviee. (2UU) (430) The email Validation Module (204) submits a query to the validation database (2U3) to determine if the submitted code and: proxy GUID
285 matches the information contained in the database: (436) If there is a matching code and corresponding matching GLJID in the validation database (203); (438; 440) then the Validation Module adds the validated email address to the AVS (202) (442) and ends a validation-accepted message to the proxy (102, 302) (444) whereupon the proxy (102, 302) enables the validated email address allowing authorized users to send and receive secure: email messages using the address.
(446, 448) If there is no 290 match for the submitted code and/or GUIDE the Validation Module (204) notifies ,the proxy ( 102, 302) that the entered codes) were invalid and the proxy (1U2, 302) advises the user that the codes they .. ~ h v."li . _._ added vvilt riot Work: ~' (450, 52) The user is t en o~'ered the ;option to try' and a date ~ariotlier einail address. (454) Moving now to Fig. 8 we will now describe how email is sent and received in a secure manner using 295 the preferred embodiment of~fhe invention. The user (the "sender")who wishes to send a secure email message prepares and sends their message using their preferred email software.
(602) If the-proxy ( 102) has been enabled to send secure email, (604) it will monitor all outbound email traffic intercepting each outbound message and parsing out all of the email addresses contained in the From, To, CC, and BCC
fields. (606) The proxy (102) then determines if the email address in the From field has been validated:
300 (608) If it has not, then the sender is asked if they want to validate the email address so that the message can be sent in. a secure manner. (61:8) If the ender does not wish to validate the email address, :,, ~. ..
c .3n*: ..
C
vL _ :_~~.:x~., f thenal~messa evis=~s~nt:.x~,.all~,:ofahe~~addr~essees~.usin :corrventlanal-email; rot~eols:. 6~6E~~ f- e< t, :,.-,,;~
g g p ( ) I th sender wants to validate the email address so that the message is sent in a secure manner; then the proxy ( 102) encrypts the message with the sender's personal encryption key; (to protect the confidentiality of the 305 message while the proxy (102) validates :the sender's email address and prepares the message for transmission) and stores the encrypted message on the sender's computer. (100) At the same time the proxy (102) creates an entry for each addressee that the message is destined to in the OMQ. (104) (621) The proxy (102) then launches the email validation process and the sender completes the validation process as previously described. (622) _11_ 310 If the email address in the From :field has been validated then the proxy ( 102) encrypts the message with the sender's personal encryption key (to protect the confidentiality of the message while the proxy ( 102) prepares the message , for transmission) and stores he encrypted message on the sender's computer: ( 100) At the same time the proxy ( 102) creates an entry for each addressee that the message is destined to in the OMQ. ( L04) (610) 315 The proxy (102) then sends a request to the AVS (202) to determine the validation status of the addresses in the To, CC and BCC fields. (612) If there are any addresses that have not been validated, (614) and if the sender has configured the proxy (102) to automatically send email messages to un-validated addresses in an unsecured manner; (624) hen the proxy (102) decrypts a copy of the message using the sender's personal decryption key (623) and sends the message to all non-validated addressees .. .. .. : 320 . . using. con~rentional .:,emait ..piotoeols.: (616) The .
proxy (102). then :.updates . each ,address in the . QMQ
( 104) to indicate that what'addresses the message was sent to using conventional email. (615) If the sender has configured the proxy (102) to notify them when there are messages destined to. non-validated addressees; then the proxy ( 102) displays a message, to the sender advising them that there are messages for non-validated addresses in the OMQ. (104) (638) The sender reviews the addressees in 325 he OMQ (104) and flags messages that may be sent in an unsecured manner.
(64.0) The proxy (102) in turn regularly monitors the OlVIQ ( 104) for messages that have been reviewed by the sender. If the sender has flagged messages that can be sent in an unsecured manner, ,(642) then the proxy ( 102) decrypts the message using the sender's personal decryption key (630) and sends the message to all of the flagged addressees using conventional email protocols: (632) < r _ ;,.~"" .
... ~. . .
s;:. -..~., Y M. ~ v .
s ~
r~ 4~.
330 ~ 'If the sender ~ lia's fla '~ ed~ ad ~ s th t u~ t ~ s t ' gg dyes es a m s be en m' a secure niaiuier,~ (~44~ ; then the proxy ( 102) uses a pre-defined message template that was created by the sender when they installed the proxy ( 102) software onto their computer to generate and send a conventional email message that advises the receiver that the sender wants to send them a secure xriessage and in order to receive the message they must install and configure the proxy (302) and validate their email address.
(646, 648) The proxy (102) 335 then begins to regularly monitor the AVS (202) for the receiver's validated email address. (649) If the message sent to the receiver bounces, (650) the proxy ( 102) updates the entry in the OMQ ( 104) to indicate that the receivers email address is invalid and discontinues monitoring the AVS (2Q2) for the receiver's address: (660) If the sender has specified that the message should be sent in an unsecured manner and if the receiver 340 has not responded to.the proxy installation and validation, reqpest after a preset period of time, (654) then the proxy (102) will discontinue monitoring the pMQ (104) for the receivers validated ernail address, (662) decrypt (663) and send the message to the receiver using conventional email protocols, (664) and updates the OMQ (104) to indicate that the receiver never validated their email address and that the message was sent in an unsecured manner using conventional email.
(665) If the sender 345 specified than the rriessage must be sent in a secure manner, then the proxy ( 102) simply continues to monitor the AVS (202) for an indefinite period of time for the receiver to validate their email address.
(658) If the receiver's email address is added to the AVS (202)' indicating that the receiver has installed and .... eonfigured,the:groxyr,(3.02) hen the ender's proxy.(102) dueries the operating ystem for it's currently .
350 assigned IP address:' (626) The IP address is ,then encrypted by the proxy ,(102) using a built in symmetrical encryption algorithm and encryption key. (628) The proxy (102) then generates a conventional email message (666) that includes: 1:) a proxy ID code in the subject line that is used by the receivers proxy (302) to intercept messages intended- for the proxy (302) (668); 2.) The sender's symmetrically encrypted IP address, and (670); 3:) a human readable message in the body of the email 355 that explains what the emaii is about in case the receivers proxy (302) fails to intercept the message, or in case the receiver has- removed the proxy (302) from their computer. (672) The proxy ( 102) then sends fhe email message to the receiver's proxy (302) using conventional email protocols: (674);
The receiver's proxy (302) monitors each incoming email message for an ID code in the Su>;ject field that tells the proxy (302) that the message was sent by anther proxy. (676) If the subject field contains 360 a proxy ID code, then the receiver's proxy (302) intercepts the message, preventing it from being forwarded to the receivers normal email software. (680) The receiver's proxy (302) then parses the message and decrypts the IP address using its built in symmetrical decryption algoritlun and decryption key. (683) The receiver's proxy (302) then attempts to establish a secure P2P
connection with the sender's proxy (102) using the IP address provided by the sender's proxy.
(i02) (684) If the receiver is 365 unable to establish a secure connection with the sender's proxy, (102) (686) the receiver's, proxy (302) composes 'and sends a conventional email message .that contains a proxy 'ID
code in the subject line, asking the sender's proxy (102) tore-send it's current IP address. (694) This process will be repeated until the receiver's proxy (302) is able to establish a secure connection with the sender's proxy; (102) _13_ or until the number of iterations reaches a value established by the sender whereupon the ender's 370 proxy (102) will either send the message in an unsecured manner, or flags the message in the ender's OMQ ( 104) as not sent due to P2P connection failure. Once a secure P2P
connection has been established between the receiver's proxy (3U2) and the sender's proxy, ( 102) the receiver's proxy (302) transmits the r~eiver's current public encryption key to the sender's proxy (102) (688) : and the sender's proxy ( 102) confirms receipt of the receiver's -public key. (690) The sender's proxy ( 102) then 375 decrypts all email messages that are destined to the r~eiver using the sender's private. decryption key, (692) and then re-encrypts each message destined to the receiver with the receiver's public encryption key. (696) The sender's proxy (102) then transmits all encrypted messages o the receiver's proxy (302) via the secure P2P channel: (698) The receiver's proxy (302) then decrypts each received message using the receiver's private decryption key (740) and confirms the successful delivery of each message ..,~..~. ..~.... , .
380-_ .:_;~o...he~.>:. .d s . , t sen er -proxy. ('102) (704) Tfa message~vi!as notauccessf"'ully recei~ed~and neeiypted;'(702) then the receiver's proxy (3U2) will send a request to the sender's proxy (102) via the secure P2P channel; to re-transmit the message. (710) Once all of the messages have been successfully transmitted and decrypted, the receiver's proxy (302) closes the P2P connection (712) and pass all of the decrypted email messages on to the receivers preferred email software. (714) Once the P2P connection has been 385 closed-by the receiver's proxy (302), the sender's proky (102) updates each-entry in the Q1VIQ (104) indicating what messages were successfully sent in a secure manner to the receiver. (706) The sender's proxy (102) then securely deletes the receiver's public keyfrom the sender's computer. (?08)
Claims (16)
We claim:
1. A method for the moderately secure transmission of email using a system comprising of: a central database and server that contains information about which computers are secure Peer-To-Peer (P2P) email enabled; an email proxy or service that provides message encryption and decryption services; a process that allows sending and receiving systems to exchange public encryption keys via a secure P2P connection, and; a validation process that provides reasonable assurance that the sender and receiver of an email message has the authority to send and receive email messages using the email addresses contained in the header portion of the email message.
2. A method for automatically and asynchronously establishing a secure P2P
connection between two systems by using standard Internet email services to exchange symmetrically encrypted computer IP information.
connection between two systems by using standard Internet email services to exchange symmetrically encrypted computer IP information.
3. The method of claim 1 comprising a centralized database that records and reports the current status of email proxy software or services that have been enabled to send and receive secure email messages via a P2P connection.
4. The method of claim 1 wherein email proxy software or other service intercepts email sent to and from an email service and provides encryption and decryption services of incoming and outgoing email messages using public key cryptography.
5. The method of claim 1 wherein email proxy software or other service is used to establish a P2P
connection between the sender's computer and the recipient's computer.
connection between the sender's computer and the recipient's computer.
6. The method of claim 1 wherein public encryption keys are securely and automatically exchanged using a P2P connection established between the sender's email proxy software or other service, and the recipient's email proxy software or other service
7. The method of claim 1 comprising of a process that validates each email address by requiring a user to register their email address with a central service
8. The method of claim 3 wherein email proxy software or other service can automatically route email via standard Internet email if the recipient does not have P2P email proxy software or service installed, and if the sender has configured the email proxy software or other service to automatically route email via standard Internet email when a secure P2P
connection cannot be established with the recipient.
connection cannot be established with the recipient.
9. The method of claim 3 wherein email proxy software or other service establishes a secure connection to a central service to report and query the status of other email proxies by email address.
10. The method of claim 1 wherein a process validates the senders email account at the time of installation of the email proxy software or other service
11. The method of claim 10 wherein a process will execute at the time of installation which will generate a globally unique string that will identify the workstation that the email proxy software or other service is installed on.
12. The method of claim 10 wherein a process is executed the first time the email proxy software or other service is run and of claim 7 to which the user's input is acquired to obtain the email address that they wish to send secured email from, and where the email proxy software or other service will not send secured email until a verification process has been completed
13. The method of claim 12 wherein the email proxy software or other service submits the email address the user enters with the installation unique identifier to the email security service and the email security service generates a random alpha-numeric code which is associated with the email account and installation unique identifier then emails the email address the random code.
14. The method of claim 12 wherein the user must enter the random code emailed to their email account into the email proxy software or other service which sends the code and installation unique identifier to the email security service to verify that the code came through the correct email box. If the email security service receives a matching code, the email address is noted as being validated and a success response is returned to the email proxy software or other service that then allows it to send secured email messages.
15. The method of claim 4 wherein messages that are waiting to be delivered to the recipient are stored in a symmetrically encrypted method on the user's computer or other device until a connection is made to the recipient's email proxy software at which time messages are decrypted and then asymmetrically encrypted with the recipients public key.
16. The method of claim 4 wherein message that have been received from a sender are stored in a symmetrically encrypted form on the users computer or other device until the user's email software makes a connection to the email proxy software at which time the messages are decrypted prior to delivery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002390817A CA2390817A1 (en) | 2002-06-28 | 2002-06-28 | Method for the moderately secure transmission of electronic mail |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002390817A CA2390817A1 (en) | 2002-06-28 | 2002-06-28 | Method for the moderately secure transmission of electronic mail |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2390817A1 true CA2390817A1 (en) | 2003-12-28 |
Family
ID=30449906
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002390817A Abandoned CA2390817A1 (en) | 2002-06-28 | 2002-06-28 | Method for the moderately secure transmission of electronic mail |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2390817A1 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2444341A (en) * | 2006-12-01 | 2008-06-04 | David Irvine | Distributed network messenger system with SPAM filtering, encryption, digital signing and digital contract generation |
| US7529937B2 (en) | 2005-03-07 | 2009-05-05 | Microsoft Corporation | System and method for establishing that a server and a correspondent have compatible secure email |
| US8028026B2 (en) | 2006-05-31 | 2011-09-27 | Microsoft Corporation | Perimeter message filtering with extracted user-specific preferences |
| EP2575298A1 (en) * | 2011-08-11 | 2013-04-03 | brainchild GmbH | Method and device for secure handling of an email message |
| US8549295B2 (en) | 2006-05-31 | 2013-10-01 | Microsoft Corporation | Establishing secure, mutually authenticated communication credentials |
| US8726020B2 (en) | 2006-05-31 | 2014-05-13 | Microsoft Corporation | Updating configuration information to a perimeter network |
| US10044735B2 (en) * | 2015-04-09 | 2018-08-07 | Secure Information Devices Inc. | System and method for authentication of electronic communications |
-
2002
- 2002-06-28 CA CA002390817A patent/CA2390817A1/en not_active Abandoned
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7529937B2 (en) | 2005-03-07 | 2009-05-05 | Microsoft Corporation | System and method for establishing that a server and a correspondent have compatible secure email |
| US8028026B2 (en) | 2006-05-31 | 2011-09-27 | Microsoft Corporation | Perimeter message filtering with extracted user-specific preferences |
| US8549295B2 (en) | 2006-05-31 | 2013-10-01 | Microsoft Corporation | Establishing secure, mutually authenticated communication credentials |
| US8726020B2 (en) | 2006-05-31 | 2014-05-13 | Microsoft Corporation | Updating configuration information to a perimeter network |
| US9160740B2 (en) | 2006-05-31 | 2015-10-13 | Microsoft Technology Licensing, Llc | Establishing secure, mutually authenticated communication credentials |
| GB2444341A (en) * | 2006-12-01 | 2008-06-04 | David Irvine | Distributed network messenger system with SPAM filtering, encryption, digital signing and digital contract generation |
| GB2446198A (en) * | 2006-12-01 | 2008-08-06 | David Irvine | Non-repudiation of messages in peer-to-peer network |
| EP2575298A1 (en) * | 2011-08-11 | 2013-04-03 | brainchild GmbH | Method and device for secure handling of an email message |
| US10044735B2 (en) * | 2015-04-09 | 2018-08-07 | Secure Information Devices Inc. | System and method for authentication of electronic communications |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |