Cryptography 9 Flashcards
different encryption keys generate the same ciphertext from the same plaintext message
Key Clustering
Synchronous: encryption or decryption request is performed immediately
Asynchronous: Encrypt/Decrypt requests are processed in queues
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Root CA – only issues certificates to Subordinate CA’s
Subordinate CA – issues certificates to users + computers on behalf of the Root CA
Registration authority (RA): responsible for the accuracy of the information contained in a certificate request. The RA is also expected to perform user validation before issuing a certificate request.
CA’s
??? provided by mixing (changing) the key values used during the repeated rounds of encryption.
??? provided by mixing up the location of the plaintext throughout the ciphertext.
Confusion / Diffusion
??? allows encryption of partial blocks rather than requiring full blocks for encryption. This eliminates the need to pad a block like in CBC.
??? mode makes a block cipher into a synchronous stream cipher. It generates keystream blocks, which are then XORed with the plaintext blocks to get the ciphertext.
CFB / OFB
Fibonacci Numbers: Sequence of numbers derived by adding the last number in the sequence to the previous one to create the next.
Pseudo-random number generators (PRNGs) are algorithms that can create long runs of numbers with good random properties, but eventually the sequence repeats.
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RSA : Based on the practical difficulty of factoring the product of two large prime numbers. Key sizes are typically from 1,024 - 4,096 bits.
Menezes-Qu-Vanstone (MQV): A protocol used for key agreement that is based on Diffie-Hellman.
RSA Etc …
EIGamal = based on DH, The algorithm consists of three parts: the key generator, the encryption algorithm, and the decryption algorithm.
Registration Authority (RA): acts as a proxy between the user and the CA. The RA receives a certificate request, authenticates it, and forwards it to the CA.
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RFC 5055. An Internet protocol for determining the path between a X.509 digital certificate and a trusted root (Delegated Path Discovery) and the validation of that path (Delegated Path Validation) according to a particular validation policy.
Server-based Certificate Validation Protocol (SCVP)
Cryptanalysis is the art or process of deciphering coded messages without being told the key.
Frequency Analysis: examining ciphertext looking for patterns that can be examined against the frequency rate of letter usage by language.
Kasiski test: A variation on frequency analysis that is used to attack polyalphabetic substitution ciphers.
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