Introduction to Cryptography - D334 questions and solutions

Introduction to Cryptography - D334 j i j i j i j i




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1. cryptography:thescienceofkeepinginformationsecretandsafebytransform- ing it ji ji ji ji ji ji ji ji ji ji ji ji




into a form that unintended recipients cannot understand using an algorithm
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2. cryptanalysis:the study of ciphertext, ciphers, and cryptosystems with the aim of ji ji ji ji ji ji ji ji ji ji ji




understandinghowtheyworkandfindingandimprovingtechniquesfordefeating or
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weakening them
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3. cryptology:thestudy and practice ofbothcryptography and cryptanalysis ji ji ji ji ji ji ji ji ji




4. LuciferCipher:-1970IBM's1stsymmetricblockcipher. ji ji ji ji ji ji ji




- Lead to DES
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5. Confusion(Cryptography):seekstohideanypatternsorrelationshipsbetween the ji ji ji ji ji ji ji ji ji ji




input and output of an encryption algorithm, thereby increasing the security of the cipher.
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typicallyachievedthroughoperationsthatmaketherelationshipbetweentheplain- text an ji ji ji ji ji ji ji ji ji ji ji ji




the ciphertext non-linear and difficult to discern.
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Thiscanincludetechniquessuchassubstitution,permutation,andnon-linear
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mathematical operations.
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6. Diffusion(cryptography):ensuresthatanypatternsintheplaintext,suchas ji ji ji ji ji ji ji ji ji ji




redundant bits, are not apparent in the ciphertext
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7. Diffie-HellmanKeyAgreementProtocol:amethodusedtoestablishashared ji ji ji ji ji ji ji ji ji ji




secret between two parties over an insecure communication channel.
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Itenablessecurecommunicationbyallowingtwopartiestogenerateasharedsecretkey
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without ever directly exchanging the key itself.
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2048bitprimenumbersistheminimumrecommendedforusewithDiffieHellman to
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counter attacks involving key precomputation.
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The major weakness with Diffie Hellman is its susceptibility to having certain para- meter
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values easily precomputed
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8. DHE (Diffie-Hellman Ephemeral): involves use of a different key for each con- ji ji ji ji ji ji ji ji ji ji ji




nection
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9. DHE-RSA: the server signs the Diffie-Hellman parameter (using a private key from ji ji ji ji ji ji ji ji ji ji ji




an RSA key pair) to create a pre-master secret, and where a master key is created
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which is then used to generate a shared symmetric encryption key.
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apre-mastersecretisusedtocreateamasterkeybyusing"Pseudorandom Function
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(PRF)"
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, Introduction to Cryptography - D334 j i j i j i j i




Study online athttps://quizlet.com/_es8r49 ji ji ji




10. DiffieHellmangroups:Group1-768-bitgroup ji ji ji ji ji ji




Group2 - 1024-bit group
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Group5 - 1536-bitgroup Group14 ji ji ji




- 2048-bit group Group15 - 3072-
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bit group Group19-256-bitelliptic
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curve Group20-384-bitelliptic
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curve Group21 - 521-bit elliptic
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curve
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Group24 - 2048-bit, 256 bit subgroup ji ji ji ji ji




11. FREAK:thevulnerabilityinDiffieHellmanthatinvolvestheeaseatwhich512-bitkeys ji ji ji ji ji ji ji ji ji ji ji ji ji




can be determined using graphic processors running in the Cloud.
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12. PrettyGoodPrivacy(PGP):awidelyusedencryptionsoftwareprogramthat ji ji ji ji ji ji ji ji ji ji




provides cryptographic privacy and authentication for data communication.
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It was created by Phil Zimmermann in 1991 and has since become one of the most
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popularmethodsforsecuringemailcommunications,filestorage,anddigital signatures.
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usesacombinationofsymmetric-keycryptographyandpublic-keycryptographyto
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encrypt and decrypt data.It typically employs a symmetric cipher (such as AES) to
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encrypttheactualdataandthenusesasymmetricencryption(basedonRSAor
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ElGamal) to securely exchange the symmetric key.
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allowsuserstocreatedigitalsignaturesforverifyingtheauthenticityandintegrityof
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messages or files.Digital signatures are generated using the sender's private key and can
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be verified by anyone who hasaccess to the sender's public key.
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incorporatesadecentralizedtrustmodelknownasthe"weboftrust."Inthismodel, users ji ji ji ji ji ji ji ji ji ji ji ji ji ji




can verify the authenticity of public keys by personally verifying the identity oftheir
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owners.Userscansigneachother'spublickeystoindicatetrust,creatinga network of
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trusted relationships.
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13. RSAAlgorithm:namedafteritsinventorsRonRivest,AdiShamir,andLeonard ji ji ji ji ji ji ji ji ji ji ji




Adleman,isawidelyusedpublic-keyencryptionscheme.It'sbasedonthepractical
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difficulty of factoring the product of two large prime numbers, known as the RSA problem,
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which forms the basis of its security.
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has a heavy overhead on processor loading and is not well suited to embedded sys- tems
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(as the power drain can be high, along with heavy requirements for processing and
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memory).
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