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AES is a variant of Rijndael, with a fixed block size of 128 bits, and a key size of 128, 192, or 256 bits. By contrast, Rijndael per se is specified with block and key sizes that may be any multiple of 32 bits, with a minimum of 128 and a maximum of 256 bits. Most AES calculations are done in a particular finite field.
As of October 2012, CNSSP-15 [4] stated that the 256-bit elliptic curve (specified in FIPS 186-2), SHA-256, and AES with 128-bit keys are sufficient for protecting classified information up to the Secret level, while the 384-bit elliptic curve (specified in FIPS 186-2), SHA-384, and AES with 256-bit keys are necessary for the protection of Top ...
There are also truncated versions of each standard, known as SHA-224, SHA-384, SHA-512/224 and SHA-512/256. These were also designed by the NSA. These were also designed by the NSA. SHA-3 : A hash function formerly called Keccak , chosen in 2012 after a public competition among non-NSA designers.
AES key schedule for a 128-bit key. Define: N as the length of the key in 32-bit words: 4 words for AES-128, 6 words for AES-192, and 8 words for AES-256; K 0, K 1, ... K N-1 as the 32-bit words of the original key; R as the number of round keys needed: 11 round keys for AES-128, 13 keys for AES-192, and 15 keys for AES-256 [note 4] W 0, W 1, ...
(NIST SP800-38A). I.e. 1-bit loss in a 128-bit-wide block cipher like AES will render 129 invalid bits before emitting valid bits. CFB may also self synchronize in some special cases other than those specified. For example, a one bit change in CFB-128 with an underlying 128 bit block cipher, will re-synchronize after two blocks.
This should be acceptable for up to 2 64 × 16 B = 256 exabytes of data, and would suffice for many years after introduction. The winner of the AES contest, Rijndael, supports block and key sizes of 128, 192, and 256 bits, but in AES the block size is always 128 bits. The extra block sizes were not adopted by the AES standard.
NetLib Encryptionizer supports AES 128/256 in CBC, ECB and CTR modes for file and folder encryption on the Windows platform. Pidgin (software), has a plugin that allows for AES Encryption; Javascrypt [8] Free open-source text encryption tool runs entirely in web browser, send encrypted text over insecure e-mail or fax machine. PyEyeCrypt [9 ...
An AES instruction set includes instructions for key expansion, encryption, and decryption using various key sizes (128-bit, 192-bit, and 256-bit). The instruction set is often implemented as a set of instructions that can perform a single round of AES along with a special version for the last round which has a slightly different method.