C178 Cryptography 2a

its4forscience's version from 2018-01-14 17:04


Question Answer
Modern cryptography is divided into three major areas:symmetric cryptography, asymmetric cryptography, and hashing algorithms
require both ends of an encrypted msg to have same key and processing algorithmsSymmetric algorithms
generate a secret key that must be protectedSymmetric algorithms
sometimes referred to as a secret key or private keysymmetric key
a key that isn't disclosed to people who aren't authorized to use the encryption systemsymmetric key
what type of cryptographic algorithm is always faster than the other?symmetric cryptographic algorithms
can be just as secure with a smaller key sizesymmetric cryptographic algorithms
algorithm works on chunks of data, encrypts one and then moves to the nextblock cipher
data is encrypted one bit, or byte, at a timestream cipher
56-bit key, replaced by AES, considered insecure because of small key sizeData Encryption Standard (DES)
more secure than DES, increases key length to 168 bits using 3 56-bit DES keysTriple-DES (3DES)
replaced DES as current standard, Rijndael algorithm, key sizes of 128, 192, 256 bits, with 128 bit defaultAdvanced Encryption Standard (AES)
uses 256 bits instead of 128, qualifies for U.S. government as Top SecretAES256 (AES-256)
used by Microsoft and IBM, uses a 40-bit to 128-bit key, very fast and efficientCAST (Carlisle Adams and Stafford Tavares) (128 and 256 also exist)
uses a key size of up to 2048 bits, considered to be a strong systemRC5, also RC stands for Ron's Cipher, from RSA labs (RC4, RC5, and RC6)
popular with wireless and WEP/WPA encryption, used in SSL and TLS, BitTorrentRC4
symmetric block cipher that uses variable-length keys, performs a 64-bit block cipher very fastBlowfish
used in Pretty Good Privacy (PGP), public domain encryption system used for emailInternational Data Encryption Algorithm (IDEA)
the only truly completely secure cryptographic implementationOne-time pad
key exchanged within same communications channel that is going to be encryptedIn-band key exchange
some other channel is used to exchange the keyOut-of-band key exchange
ensures if one key is compromised subsequent keys will not be compromisedForward secrecy
uses two keys to encrypt and decrypt dataAsymmetric algorithms
cannot be used to decrypt a messagepublic key