Computer Security by William Stalling CH 2 MCQ
Computer Security by William Stalling CH 2 MCQ
Computer Security by William Stalling CH 2 MCQ
Chapter 2
Chapter2CryptographicTools
TRUE/FALSEQUESTIONS:
1.Symmetricencryptionisusedprimarilytoprovideconfidentiality.
2.Twoofthemostimportantapplicationsofpublickeyencryptionare
digitalsignaturesandkeymanagement.
3.Cryptanalyticattackstryeverypossiblekeyonapieceofciphertext
untilanintelligibletranslationintoplaintextisobtained.
4.Thesecretkeyisinputtotheencryptionalgorithm.
5.TripleDEStakesaplaintextblockof64bitsandakeyof56bitsto
produceaciphertextblockof64bits.
6.Modesofoperationarethealternativetechniquesthathavebeen
developedtoincreasethesecurityofsymmetricblockencryptionfor
largesequencesofdata.
7.Theadvantageofastreamcipheristhatyoucanreusekeys.
8.Amessageauthenticationcodeisasmallblockofdatageneratedbya
secretkeyandappendedtoamessage.
9.LiketheMAC,ahashfunctionalsotakesasecretkeyasinput.
10.Thestrengthofahashfunctionagainstbruteforceattacksdepends
solelyonthelengthofthehashcodeproducedbythealgorithm.
11.Publickeycryptographyisasymmetric.
12.Publickeyalgorithmsarebasedonsimpleoperationsonbitpatterns.
TF
13.ThepurposeoftheDSSalgorithmistoenabletwouserstosecurely
reachagreementaboutasharedsecretthatcanbeusedasasecretkey
forsubsequentsymmetricencryptionofmessages.
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14.Animportantelementinmanycomputersecurityservicesand
applicationsistheuseofcryptographicalgorithms.
Chapter 2
15.Someformofprotocolisneededforpublickeydistribution.
MULTIPLECHOICEQUESTIONS:
1. Theoriginalmessageordatathatisfedintothealgorithmis__________.
A.encryptionalgorithm
B.secretkey
C.decryptionalgorithm
D.plaintext
2. The__________istheencryptionalgorithmruninreverse.
A.decryptionalgorithm
B.plaintext
C.ciphertext
D.encryptionalgorithm
3.__________isthescrambledmessageproducedasoutput.
A.Plaintext
B.Ciphertext
C.Secretkey
D.Cryptanalysis
4.Onaverage,__________ofallpossiblekeysmustbetriedinordertoachieve
successwithabruteforceattack.
A.onefourth
B.half
C.twothirds
D.threefourths
5.Themostimportantsymmetricalgorithms,allofwhichareblockciphers,arethe
DES,tripleDES,andthe__________.
A.SHA
B.RSA
C.AES
D.DSS
6.Iftheonlyformofattackthatcouldbemadeonanencryptionalgorithmisbrute
force,thenthewaytocountersuchattackswouldbeto__________.
B.useshorterkeys
C.usemorekeys
D.uselesskeys
Chapter 2
7.__________isaprocedurethatallowscommunicatingpartiestoverifythatreceived
orstoredmessagesareauthentic.
A.Cryptanalysis
B.Decryption
C.Messageauthentication
D.Collisionresistance
8.Thepurposeofa__________istoproduceafingerprintofafile,message,or
otherblockofdata.
A.secretkey
B.digitalsignature
C.keystream
D.hashfunction
9.__________isablockcipherinwhichtheplaintextandciphertextareintegers
between0andn1forsomen.
A.DSS
B.RSA
C.SHA
C.AES
10.A__________iscreatedbyusingasecurehashfunctiontogenerateahashvalue
foramessageandthenencryptingthehashcodewithaprivatekey.
A.digitalsignature
B.keystream
C.onewayhashfunction
D.secretkey
11.Transmitteddatastoredlocallyarereferredtoas__________.
A.ciphertext
B.DES
C.dataatrest
D.ECC
Chapter 2
12.Digitalsignaturesandkeymanagementarethetwomostimportantapplicationsof
__________encryption.
A.privatekey
B.publickey
C.preimageresistant
C.advanced
13.A__________istotryeverypossiblekeyonapieceofciphertextuntilan
intelligibletranslationintoplaintextisobtained.
A.modeofoperation
B.hashfunction
C.cryptanalysis
D.bruteforceattack
14.CombinedonebyteatatimewiththeplaintextstreamusingtheXORoperation,a
__________istheoutputofthepseudorandombitgenerator.
A.keystream
B.digitalsignature
C.securehash
D.messageauthenticationcode
15.A_________protectsagainstanattackinwhichonepartygeneratesamessagefor
anotherpartytosign.
A.dataauthenticator
B.stronghashfunction
C.weakhashfunction
D.digitalsignature
SHORTANSWERQUESTIONS:
1. Alsoreferredtoassinglekeyencryption,theuniversaltechniqueforproviding
confidentialityfortransmittedorstoreddatais__________.
2. Therearetwogeneralapproachestoattackingasymmetricencryptionscheme:
cryptanalyticattacksand__________attacks.
3. The__________algorithmtakestheciphertextandthesecretkeyandproduces
theoriginalplaintext.
4. A__________attackexploitsthecharacteristicsofthealgorithmtoattemptto
deduceaspecificplaintextortodeducethekeybeingused.
Chapter 2
5. A__________processestheplaintextinputinfixedsizeblocksandproducesa
blockofciphertextofequalsizeforeachplaintextblock.
6. A__________processestheinputelementscontinuously,producingoutputone
elementatatime.
7. Publickeyencryptionwasfirstpubliclyproposedby__________in1976.
8. Thetwocriteriausedtovalidatethatasequenceofnumbersisrandomare
independenceand_________.
9. A_________isahardwaredevicethatsitsbetweenserversandstoragesystems
andencryptsalldatagoingfromtheservertothestoragesystemanddecrypts
datagoingintheoppositedirection.
10. InJuly1998the__________announcedthatithadbrokenaDESencryption
usingaspecialpurposeDEScrackermachine.
11. Thesimplestapproachtomultipleblockencryptionisknownas__________
mode,inwhichplaintextishandledbbitsatatimeandeachblockofplaintextis
encryptedusingthesamekey.
12. A__________streamisonethatisunpredictablewithoutknowledgeoftheinput
keyandwhichhasanapparentlyrandomcharacter.
13. The__________isapairofkeysthathavebeenselectedsothatifoneisusedfor
encryption,theotherisusedfordecryption.
14. __________isprovidedbymeansofacoprocessorboardembeddedinthetape
driveandtapelibraryhardware.
15. Thepurposeofthe__________algorithmistoenabletwouserstosecurely
reachagreementaboutasharedsecretthatcanbeusedasasecretkeyfor
subsequentsymmetricencryptionofmessages.
Chapter2CryptographicTools
AnswerKey
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MULTIPLECHOICEQUESTIONS:
1. D
2. A
3. B
4. B
5. C
6. A
7. C
8. D
9. B
10. A
11. C
12. B
13. D
14. A
15. B
SHORTANSWERQUESTIONS:
1. symmetricencryption
2. bruteforce
3. decryption
Chapter 2
Chapter 2