WO2024148970A1

WO2024148970A1 - Decentralized domain name resolution method and apparatus based on handle system

Info

Publication number: WO2024148970A1
Application number: PCT/CN2023/133858
Authority: WO
Inventors: 张海阔; 叶崛宇; 吕万波; 胡卫宏; 伦占群
Original assignee: 中国互联网络信息中心
Priority date: 2023-01-09
Filing date: 2023-11-24
Publication date: 2024-07-18
Also published as: CN116170403A; CN116170403B

Abstract

The present invention relates to the technical field of computers, and in particular to a decentralized domain name resolution method and apparatus based on a handle system. The method comprises: acquiring domain name system root zone data on the basis of a domain name multi-center root system of a preset handle system; receiving a domain name query inputted by a user; according to the domain name system root zone data, acquiring top-level domain name information corresponding to a domain name that needs to be queried; acquiring domain name information of each level according to the top-level domain name information; and sending a domain name query to an authoritative resolution service address of acquired last-level domain name information, so as to acquire a final domain name resolution result. The present invention aims to solve the problem of a domain name system being vulnerable due to a centralized structure of a conventional domain name system leading to serious reliance on a root domain name server and there being single-side management and closed management involved in the domain name system.

Description

Decentralized domain name resolution method and device based on Handle system

Technical Field

The present invention relates to the field of computer technology, and in particular to a decentralized domain name resolution method and device based on a Handle system.

Background technique

Currently, the namespace structure, domain name allocation and resolution process of the domain name system are strictly hierarchical. The root resolution system is the starting point of domain name resolution and the center of the system structure. It is mainly composed of the root zone data management system that manages and maintains top-level domain name information and the root server system that provides resolution services.

The Handle System uses the handle as the unique identifier of a digital object in order to provide services such as permanent identification, dynamic resolution, and security management for digital objects. As a general name service system, the Handle System has been deployed on the Internet for more than 20 years and currently registers and manages more than 1 billion identifiers.

Each Handle has its own namespace. A Handle consists of two parts: a naming authority, called a prefix, and a unique local name under that naming authority, called a suffix. The naming authority and the local name are separated by the ASCII character "/". Therefore, a handle can be defined as follows:

<Handle>::＝<Handle Naming Authority>“/”<Handle Local Name>.

All local names under this naming authority form the local Handle namespace under this naming authority. For example, "10.1045/january99-bearman" is the Handle of an article in D-Lib magazine. The naming authority of this Handle is "10.1045", and "january99-bearman" is a local name. At present, the root zone data management is mainly responsible for the Internet Corporation for Assigned Names and Numbers (ICANN) and its affiliated companies, which has problems such as unilateral management. At the same time, 13 root servers and their mirror servers are operated by 12 organizations, which has problems such as closed management. However, the centralized structure of the traditional domain name system is prone to serious dependence on the root domain name server. When the data is centralized in a certain organization for management, data errors may occur due to operational errors or intentional tampering or deletion by humans, which will eventually lead to errors in the root zone data of the entire domain name system (DNS system), causing large-scale network disconnection or inaccessibility to the Internet in a certain area, resulting in the vulnerability of the domain name system.

Summary of the invention

The present invention provides a decentralized domain name resolution method and device based on a Handle system, which is used to solve the problem that the centralized structure of the traditional domain name system causes a serious dependence on the root domain name server, and the domain name system has unilateral management and closed management, which leads to the vulnerability of the domain name system.

The present invention provides a decentralized domain name resolution method based on a Handle system, comprising:

Based on the domain name multi-center root system of the preset Handle system, obtain the domain name system root zone data;

Receive domain name query input by the user;

According to the domain name system root zone data, obtaining top-level domain name information corresponding to the domain name to be queried;

According to the top-level domain name information, obtain domain name information at all levels;

Send a domain name query to the authoritative resolution service address of the last-level domain name information obtained to obtain the final domain name resolution result;

Among them, the domain name multi-center root system based on the preset Handle system is based on each root node in the Handle system to obtain each Handle top-level domain name node, and the various Handle top-level domain name nodes are independent of each other and mirror each other.

According to a decentralized domain name resolution method based on a Handle system provided by the present invention, the domain name multi-center root system based on a preset Handle system obtains domain name system root zone data, including:

Based on the multi-center root system of the domain name of the preset Handle system, the Handle query service agent is triggered by query to obtain the root zone data of the domain name system;

Or, based on the domain name multi-center root system of the preset Handle system, the Handle query service agent queries the Handle system for top-level domain name information to form new root zone data;

According to the new root zone data, a local root zone authoritative service is created to obtain the domain name system root zone data.

According to a decentralized domain name resolution method based on a Handle system provided by the present invention, the step of obtaining top-level domain name information corresponding to the domain name to be queried according to the root zone data of the domain name system also includes:

Determine whether the minimum lifetime of the top-level domain name information has expired, and if so, obtain the latest domain name system root zone data.

According to a decentralized domain name resolution method based on a Handle system provided by the present invention, after the step of sending a domain name query to the authoritative resolution service address of the acquired last-level domain name information to obtain the final domain name resolution result, the method further includes:

Send a response to the final domain name resolution result;

After the response, if the domain name resolution service needs to be continued, the recursive domain name resolution service continues to receive domain name queries.

According to a decentralized domain name resolution method based on a Handle system provided by the present invention, the domain name multi-center root system based on the preset Handle system is based on each root node in the Handle system to obtain each Handle top-level domain name node, and each Handle top-level domain name node is independent of each other and is a mirror image of each other, and also includes specific construction steps, including:

Register the Handle top-level domain name node with each root node in the Handle system;

The domain name system root zone data is configured according to the Handle top-level domain name node.

According to a decentralized domain name resolution method based on a Handle system provided by the present invention, the multi-center root system of domain names based on a preset Handle system, in the step of obtaining the root zone data of the domain name system, further includes a Handle The operation and maintenance steps of the top-level domain name node include:

The hosting service provider creates the Handle resource information mapped to the top-level domain name;

Apply for the management identity and management authority of the Handle logo from the hosting service provider;

The Handle resource information management protocol is used to host the Handle top-level domain name node after authentication of the management identity and verification of management authority.

According to a decentralized domain name resolution method based on a Handle system provided by the present invention, the storage rules of the top-level domain name information stored in the Handle top-level domain name node are as follows:

Map the resource record of the top-level domain name to the Handle identifier: the Handle identifier value of the root node .111/top-level domain name and the local identifier value;

If the Handle top-level domain name node is associated with other Handle top-level domain name node identification information, the Handle identification: Handle top-level domain name node/other top-level domain name is stored as a Handle identification value of the HS_ALIAS type and points to the Handle top-level domain name node/top-level domain name.

The present invention also provides a decentralized domain name resolution system based on the Handle system, comprising:

A receiving module is used to obtain the root zone data of the domain name system based on the multi-center root system of the domain name of the preset Handle system;

And used to receive domain name query input by users;

A parsing module, used to obtain top-level domain name information corresponding to the domain name to be queried according to the domain name system root zone data;

The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the decentralized domain name resolution method based on the Handle system as described above is implemented.

The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the decentralized domain name resolution method based on the Handle system as described in any one of the above is implemented.

The present invention provides a decentralized domain name resolution method and device based on the Handle system. Through the decentralized domain name resolution method based on the Handle system, the multi-center Handle top-level domain name node in the domain name multi-center root system based on the preset Handle system replaces the original centralized domain name root system to provide root zone data and resolution services for domain name services, thereby improving the stability of domain name system services. At the same time, the root zone data of the traditional domain name system is changed. The model of unified management by a central node realizes the decentralization of the domain name system and avoids problems such as unilateral management and closed management of the domain name system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a decentralized domain name resolution method based on a Handle system provided by the present invention;

FIG2 is a schematic structural diagram of a decentralized domain name resolution device based on a Handle system provided by the present invention;

FIG3 is a schematic diagram of the structure of an electronic device provided by the present invention;

FIG4 is a schematic diagram of generating a Handle top-level domain name node in the present invention;

FIG5 is a schematic diagram of a decentralized domain name resolution architecture based on the Handle system provided by the present invention.

Detailed ways

The following describes a decentralized domain name resolution method based on a Handle system of the present invention in conjunction with FIG1 , including:

S1. Based on the domain name multi-center root system of the preset Handle system, obtain the domain name system root zone data. At the same time, the recursive domain name resolution service caches the obtained domain name system root zone data for subsequent domain name recursive resolution processes.

Specifically, there are two ways to obtain the domain name system (DNS) root zone data. The first one: based on the domain name multi-center root system of the preset Handle system, the Handle query service agent is triggered by query to obtain the domain name root zone data. For example, the client queries the A record (A: IPv4 address) corresponding to the domain name "www.12306.cn". After receiving the query, the recursive server first obtains the top-level domain name CN domain name information from the Handle query service agent. The Handle query service agent queries the Handle value of the Handle identifier "86.111/CN" and other related identification information and returns it to the recursive server. The recursive server continues to perform recursive queries on the domain name.

The second method is to use a multi-center root system for domain names based on a preset Handle system. The Handle query service agent queries the Handle system for top-level domain name information in turn to form new root zone data. Based on the new root zone data, a local root zone authoritative service is created to obtain the domain name system root zone data.

For example, the Handle query service agent can initiate a handle query to 86.111 (cn) to obtain the DNS data of cn. At the same time, the Handle query service agent can also initiate a handle query to 77.111 (ru) to obtain the DNS data of ru, and so on, to obtain all DNS top-level domain data, form new root zone data, and finally create a local root zone authoritative service based on the new root zone data to obtain the domain name system root zone data.

S2. Receive the domain name query input by the user. Specifically, receive the client domain name query through the recursive domain name resolution service. For example, the client queries the A record of the domain name "www.cnnic.cn".

S3. According to the root zone data of the domain name system, obtain the top-level domain name information corresponding to the domain name to be queried. For example, the client queries the A record of the domain name "www.cnnic.cn", and the domain name resolution service obtains the authoritative service information "a.dns.cn.172800 IN A 203.119.25.1" of the top-level domain name CN from the cached root zone data.

At the same time, the recursive domain name resolution service determines whether the minimum time to live (TTL) of the top-level domain name information has expired, and if so, executes S2 to obtain the latest domain name system root zone data. In this embodiment, the minimum time to live is 50.

For example, the domain name a.dns.cn has two A records as follows:

(1): a.dns.cn.100 IN A 203.119.25.1.

(2): a.dns.cn.50 IN A 203.119.25.1.

That is, the TTL of records (1) and (2) are 100 and 50 respectively.

S4. Obtain domain name information at all levels based on the top-level domain name information. Specifically, the recursive domain name resolution service obtains domain name information from the top-level domain name authoritative service and other authoritative resolution services at all levels. For example: the client queries the A record of the domain name "www.cnnic.cn", and the recursive resolution service obtains the domain name information "cnnic.cn.600 IN A 159.226.6.133" from the next-level authoritative resolution service "cnnic.cn" from the top-level domain authoritative service ".cn" (IP address obtained in step S4: 203.119.25.1).

S5. Send a domain name query to the authoritative resolution service address of the acquired last-level domain name information to obtain the final domain name resolution result. For example: the client queries the A record of the domain name "www.cnnic.cn", and the recursive resolution service sends a domain name request to the authoritative resolution service "cnnic.cn" (IP address obtained in step S5: 159.226.6.133) and obtains the final domain name resolution result.

In this embodiment, after the step of sending a domain name query to the address of the acquired last-level authoritative resolution service information to obtain the final domain name resolution result, the following step is further included:

Send a response to the final domain name resolution result. Specifically, send a response to the final domain name resolution result through a recursive resolution service.

After the response, if the domain name resolution service needs to be continued, the recursive domain name resolution service continues to receive domain name queries. That is, after the response, the recursive domain name resolution service determines whether to continue the domain name resolution service. If yes, it continues to receive the domain name query of the client; if not, it exits the recursive resolution service.

Among them, please refer to Figure 4. The domain name multi-center root system based on the preset Handle system is based on each root node in the Handle system to obtain each Handle top-level domain name node, and the each Handle top-level domain name node is independent and mirrored to each other.

The Handle technology used in the present invention has two obvious characteristics: First, the basis for the use of the Handle system is that a complete set of root nodes must be set up all over the world. These root nodes are independent of each other and mirror each other, forming a multi-center root node architecture of the Handle system. Second, Handle is equipped with some self-definable coding functions. Users can set part of the original coding system as self-definition according to their own ideas and needs, making the Handle technology more flexible in use. The multi-center management and flexible coding function of the Handle system provide a new technical means for the decentralized implementation of the domain name system.

By providing top-level domain name information resolution for the domain name system in a multi-center root system of domain names based on a preset Handle system, a multi-center domain name service system is constructed to provide domain name resolution services for global users. At the same time, the multi-center Handle top-level domain name node replaces the original centralized domain name root system to provide root zone data management and resolution services for domain name services, thereby improving the stability of domain name system services. In addition, the traditional mode of unified management of root zone data of the domain name system by a central node is changed to realize the decentralization of the domain name system, solving the unilateral problems and closed management of the domain name system.

Specifically, based on the domain name system of the preset Handle system, the default Handle system 111. is the Handle top-level domain name node, that is, the <Handle Naming Authority> of the top-level domain name in the Handle system is <root node.111>; multiple Handle top-level domain name nodes constitute a multi-center domain name resolution root service. Taking the top-level domain name CN as an example, 86.111 is the Handle identification authority service of the top-level domain name CN.

In this embodiment, the domain name multi-center root system based on the preset Handle system is based on each root node in the Handle system. Each root node is independent of each other and is a mirror image of each other. The specific construction steps include:

Register the Handle top-level domain name node with each root node in the Handle system. For example, the top-level domain name owner registers the Handle top-level domain name node 86.111 with the Handle China root node.

The domain name system root zone data is configured according to the Handle top-level domain name node. Specifically, the top-level domain name owner builds the Handle top-level domain name node and configures the Handle domain name system root zone data of the top-level domain name. For example: the top-level domain name node CN is configured with the Handle identifier "86.111/CN" value DNS.NS type record, and the related identifier "86.111/A.DNS.CN" value DNS.A type record and other information.

The Handle top-level domain name node receives top-level domain name information queries and makes corresponding responses to provide domain name system root zone data services for the entire network. For example: The Handle top-level domain name node receives top-level domain name CN related information queries and provides top-level domain name CN information services.

The top-level domain name information stored in the Handle identification authority service (Handle top-level domain name node) to which the top-level domain name belongs can follow the following rules.

1) The resource record of the top-level domain name can be mapped to the Handle value of the Handle identifier "root node.111/top-level domain name" and the related local identifier value. The domain name information of the top-level domain name CN is in the Handle identifier in the Handle top-level domain name node to which it belongs. The Handle identifier "86.111/CN" has several DNS.NS type Handle values (for example: a.dns.cn); the Handle identifier "86.111/A.DNS.CN" has several DNS.A type Handle values (for example: 203.119.25.1).

2) The Handle top-level domain name node is associated with other Handle top-level domain name node identification information. The Handle identifier "Handle top-level domain name node/other top-level domain name" has an alias (HS_ALIAS) type Handle identifier value "Handle top-level domain name node/top-level domain name". The Handle identifier authoritative service (86.111) to which the top-level domain name CN belongs contains other top-level domain node information (77.111/RU). Its purpose is to create a local identifier "86.111/RU" so that it contains a HS_ALIAS type Handle value and points to the Handle identifier "77.111/RU". Based on this design, the Handle query of the top-level domain name RU information of the Handle identifier authoritative service to which the top-level domain name CN belongs can be directed to the Handle identifier authoritative service (77.111) to which the top-level domain name RU belongs.

At the same time, the multi-center root system of domain names based on the preset Handle system, the step of the recursive domain name resolution service obtaining the root zone data of the domain name system, also includes the operation and maintenance trusteeship step of the top-level domain name node, including:

Step 1: The hosting service provider creates the Handle resource information mapped to the top-level domain name. Specifically, negotiate with the hosting service provider and create the Handle resource information mapped to the top-level domain name. Taking UK hosted in the Handle top-level domain name node CN as an example, its domain name information is mapped to the Handle resource information as {86.111/UK DNS.NS nsa.nic.uk.}, etc. Without modifying the Handle protocol and DNS protocol, it is compatible with both identity resolutions The technical features of the system realize the mapping design from domain name data to Handle data information, and create a new domain name resolution system that integrates multiple identification systems.

Step 2: Apply to the hosting service provider for the management identity and management authority of the Handle identifier. Specifically, the custodian applies to the hosting service provider for the management identity and management authority (addition, deletion, modification, query, etc.) of the relevant Handle identifier.

Step 3: Use the Handle resource information management protocol to host the Handle top-level domain name node after authentication of the management identity and verification of management authority. Specifically, the host manages the Handle resource record information containing domain name information after identity authentication and authority verification through the Handle resource information management protocol. The encryption mechanism of the Handle protocol itself can also ensure the privacy and integrity of management information. A new model is implemented in which the creation, management, and operation and maintenance of the full amount of top-level domain name data (top-level domain name root zone data, top-level domain name authoritative data) are independently controllable by the owner.

Decoupling of data management and operation and maintenance is achieved through identity authentication and permission control. The limitations of traditional domain name system root zone data management are broken. While having the right to manage data, tedious operation and maintenance activities can be entrusted to a third party.

The decentralized domain name resolution system based on the Handle system provided by the present invention is described below. The decentralized domain name resolution system based on the Handle system described below and the decentralized domain name resolution method based on the Handle system described above can refer to each other.

Please refer to FIG. 2 , which shows a decentralized domain name resolution system based on the Handle system, including a receiving module 210 and a resolution module 220 .

The receiving module 210 is used to obtain the domain name system root zone data based on the domain name multi-center root system of the preset Handle system.

The receiving module 210 is used to receive a domain name query input by a user.

The parsing module 220 is used to obtain the top-level domain name information corresponding to the domain name to be queried according to the domain name system root zone data;

Send a domain name query to the authoritative resolution service address of the last-level domain name information obtained to obtain the final domain name resolution result.

FIG3 illustrates a schematic diagram of the physical structure of an electronic device. As shown in FIG3 , the electronic device may include: a processor 310, a communications interface 320, a memory 330, and a communication bus 340, wherein the processor 310, the communications interface 320, and the memory 330 communicate with each other through the communication bus 340. The processor 310 may call the logic instructions in the memory 330 to execute a decentralized domain name resolution method based on the Handle system, and the method includes:

S1. Based on the domain name multi-center root system of the preset Handle system, obtain the domain name system root zone data;

S2, receiving a domain name query input by a user;

S3. Acquire the top-level domain name information corresponding to the domain name to be queried according to the domain name system root zone data;

S4. Obtain domain name information at all levels according to the top-level domain name information;

S5. Send a domain name query to the authoritative resolution service address of the acquired last-level domain name information to obtain the final domain name resolution result;

In addition, please refer to FIG. 5 , the electronic device may be a recursive server. The logic instructions in the above-mentioned memory 330 may be implemented in the form of a software functional unit and may be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk.

On the other hand, the present invention further provides a computer program product, the computer program product includes a computer program, the computer program can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer can execute the decentralized domain name resolution method based on the Handle system provided by the above methods, the method including:

S1. Obtain the initialized recursive domain name resolution service.

S2, a domain name multi-center root system based on a preset Handle system, the recursive domain name resolution service obtains S1, a domain name multi-center root system based on a preset Handle system, and obtains domain name system root zone data;

S2, receiving a domain name query input by a user;

In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to execute the decentralized domain name resolution method based on the Handle system provided by the above methods, the method comprising:

S2, receiving a domain name query input by a user;

Claims

A decentralized domain name resolution method based on a Handle system, characterized by comprising:

Based on the domain name multi-center root system of the preset Handle system, obtain the domain name system root zone data;

Receive domain name query input by the user;

According to the domain name system root zone data, obtaining top-level domain name information corresponding to the domain name to be queried;

According to the top-level domain name information, obtain domain name information at all levels;

Send a domain name query to the authoritative resolution service address of the last-level domain name information obtained to obtain the final domain name resolution result;

Among them, the domain name multi-center root system based on the preset Handle system is based on each root node in the Handle system to obtain each Handle top-level domain name node, and the various Handle top-level domain name nodes are independent of each other and mirror each other.
The decentralized domain name resolution method based on the Handle system according to claim 1 is characterized in that the domain name multi-center root system based on the preset Handle system obtains the domain name system root zone data, including:

Based on the multi-center root system of the domain name of the preset Handle system, the Handle query service agent is triggered by query to obtain the root zone data of the domain name system;

Or, based on the domain name multi-center root system of the preset Handle system, the Handle query service agent queries the Handle system for top-level domain name information to form new root zone data;

According to the new root zone data, a local root zone authoritative service is created to obtain the domain name system root zone data.
The decentralized domain name resolution method based on the Handle system according to claim 1 is characterized in that, while the step of obtaining the top-level domain name information corresponding to the domain name to be queried according to the domain name system root zone data, it also includes:

Determine whether the minimum lifetime of the top-level domain name information has expired, and if so, obtain the latest domain name system root zone data.
The decentralized domain name resolution method based on the Handle system according to claim 1 is characterized in that after the step of sending a domain name query to the authoritative resolution service address of the acquired last-level domain name information to obtain the final domain name resolution result, it also includes:

Send a response to the final domain name resolution result;

After the response, if the domain name resolution service needs to be continued, the recursive domain name resolution service continues to receive domain name queries.
According to any one of claims 1 to 4, the decentralized domain name resolution method based on the Handle system is characterized in that the domain name multi-center root system based on the preset Handle system is based on each root node in the Handle system to obtain each Handle top-level domain name node, and each Handle top-level domain name node is independent of each other and is a mirror image of each other, and also includes specific construction steps, including:

Register the Handle top-level domain name node with each root node in the Handle system;

The domain name system root zone data is configured according to the Handle top-level domain name node.
According to claim 5, the decentralized domain name resolution method based on the Handle system is characterized in that the step of obtaining the domain name system root zone data based on the preset Handle system multi-center root system also includes the operation and maintenance hosting step of the Handle top-level domain name node, including:

Create the Handle resource information mapped to the top-level domain name;

Apply for the management identity and management authority of the Handle logo;

The Handle resource information management protocol is used to host the Handle top-level domain name node after authentication of the management identity and verification of management authority.
According to the decentralized domain name resolution method based on the Handle system of claim 6, it is characterized in that the storage rules of the top-level domain name information stored in the Handle top-level domain name node are as follows:

Map the resource record of the top-level domain name to the Handle identifier: the Handle identifier value of the root node .111/top-level domain name and the local identifier value;

If the Handle top-level domain name node is associated with other Handle top-level domain name node identification information, the Handle identification: Handle top-level domain name node/other top-level domain name is stored as a Handle identification value of the HS_ALIAS type and points to the Handle top-level domain name node/top-level domain name.
A decentralized domain name resolution device based on a Handle system, comprising:

A receiving module is used to obtain the root zone data of the domain name system based on the multi-center root system of the domain name of the preset Handle system;

Receive domain name query input by the user;

A parsing module, used to obtain top-level domain name information corresponding to the domain name to be queried according to the domain name system root zone data;

According to the top-level domain name information, obtain domain name information at all levels;

Send a domain name query to the authoritative resolution service address of the last-level domain name information obtained to obtain the final domain name resolution result;

Among them, the domain name multi-center root system based on the preset Handle system is based on each root node in the Handle system to obtain each Handle top-level domain name node, and the various Handle top-level domain name nodes are independent of each other and mirror each other.
An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the decentralized domain name resolution method based on the Handle system as claimed in any one of claims 1 to 7 is implemented.
A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the decentralized domain name resolution method based on the Handle system as described in any one of claims 1 to 7 is implemented.