Cryptography Extra 6

Question 1

is used to take the burden off of a CA by handling verification prior to certificates being issued. An RA acts as a proxy between the user and the CA. The RA receives request, authenticates it, and forwards it to the CA.

Answer 1

Registration Authority (RA)

Question 2

this is a network of trusted certificate authority servers, and is the infrastructure for distributing digital certificates that contain public keys. A PKI is an arrangement that binds public keys with respective user identities by means of a CA.

*** PGP can be used to create certificates and can contain multiple sign.’s.

Answer 2

PKI Etc …

Question 3

JUNIPER, MAYFLY, FASTHASH, WALBURN, PEGASUS

Answer 3

Type 1 Algorithms

Question 4

Skipjack, KEA

Answer 4

Type 2 Algorithms

Question 5

DES, 3DES, SHA, AES

Answer 5

Type 3 Algorithms

Question 6

the attacker obtains the ciphertexts corresponding to a set of plaintexts of his own choosing. This can allow the attacker to attempt to derive the key used and thus decrypt other messages encrypted with that key.

*** Ciphertext-only : attacker only has access to a collection of cipher texts.

Answer 6

Chosen Plaintext Attack Etc …

Question 7

attacker can obtain ciphertexts encrypted under 2 different ways where subsequent keys can be derived from previous keys.

Answer 7

Related-Key Attack

Question 8

finding affine approximations to the action of a cipher used commonly on block ciphers, given enough pairs of plaintext and corresponding ciphertext bits of info about key can be obtained.

Answer 8

Linear Cryptanalysis

Question 9

for symmetric key, examining of differences in input and how that affects the result difference in the output.

Answer 9

Differential Cryptanalysis