tylercyber
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4 years ago AES: (Advanced Encryption Standard)
Based upon a subset of Rjindael’s block cipher Incoroporates a substitutio-permutation network (A series of mathematical equations utilized to generate AES ciphers) Operates on a 4 x 4 column major order, usually in a particular finite field (not infinite field arithmetic) Key sizes utilized by AES include 128, 160, 192, 224, 256. Only 128, 192 and 256 bits are specifically used by the AES standard Block sizes include the same sizes that the keys use, however only the 128 bit block size is used in the AES standard model AES has KAT tests vectors which are essentially a set of known AES ciphers for a specific input and key.
RC4: RC4 is a stream cipher, where plaintext digits are combined with a pseudorandom cipher digit stream. Each plaintext digit is encrypted one at a time to the appropriately corresponding digit of the keystream. Renowned for its simplicity and speed in software, multiple vulnerabilities exist within RC4 making it an insecure system. In 2015 experts in cryptography speculated that some nations possessed the resources to break the RC4 cipher when paired with the TLS protocol. There have been various updated versions of RC4 which attempted to mitigate these existing vulnerabilities
RC5: RC5 is unlike other cryptography models utilizing a variable block size and number of rounds. Incorporates data-dependent rotations. Simple compared to other encryption methods While 12 rounds with 64 blocks are currently susceptible to differential attacks, RC5 remains secure when concerning 18-20 rounds and still has yet to be cracked.
RC6: As its name implies it is directly derived from RC5, however it does not utilize variable block size. Rather RC6 uses a fixed block size of 128 bits, with key sizes of 128, 192, 256, 2040. Has been described as an interweaving of two parallel RC5 encryption methods, without variable block size. Plaintext is stored in four bit input registers Possibly utilized by the NSA (National Security Agency) Does not use the extra multiplication operation present in RC5
DES: (Data Encryption Standard) Renowned for being particularly insecure due to its incredibly short key length of only 56 bits. Was able to be broken in roughly 22 hours 15 minutes Was superseded by AES, is no longer considered a standard means of encryption by the National Institute of Standards and Technology.
3DES: Replaced DES due to its various vulnerabilities, however utilizes the same algorithm Runs the DES algorithm three times with three 56 bit keys. (key one is used to encrypt plaintext > key two is utilized to decrypt encoded text > key three is utilized to encrypt the text decrypted by key two.) The main benefit of 3DES is that by using a separate key to decrypt the data it makes it that much harder to decipher. Incorporates three keying options: Option one uses three independent keys and is considered the most secure option, Option two makes the first and third keys are the same and Option three uses three identical keys (The same as regular DES).
Analysis of existing symmetric encryption methods such as AES, RC4, RC5, RC6, DES, 3DES identify strengths and weaknesses. Will be utilized in the analysis of both symmetric and asymmetric encryption.