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The propagating cipher block chaining [25] or plaintext cipher-block chaining [26] mode was designed to cause small changes in the ciphertext to propagate indefinitely when decrypting, as well as when encrypting. In PCBC mode, each block of plaintext is XORed with both the previous plaintext block and the previous ciphertext block before being ...
Pages in category "Block cipher modes of operation" ... Block cipher mode of operation; A. AES-GCM-SIV; C. CBC-MAC; CCM mode; CWC mode; D. Disk encryption theory; E.
Block ciphers can be used to build other cryptographic primitives, such as those below. For these other primitives to be cryptographically secure, care has to be taken to build them the right way. Stream ciphers can be built using block ciphers. OFB mode and CTR mode are block modes that turn a block cipher into a stream cipher.
GCM uses a block cipher with block size 128 bits (commonly AES-128) operated in counter mode for encryption, and uses arithmetic in the Galois field GF(2 128) to compute the authentication tag; hence the name. Galois Message Authentication Code (GMAC) is an authentication-only variant of the GCM which can form an incremental message ...
Ciphertext stealing for ECB mode requires the plaintext to be longer than one block. A possible workaround is to use a stream cipher-like block cipher mode of operation when the plaintext length is one block or less, such as the CTR, CFB or OFB modes. Ciphertext stealing for CBC mode doesn't necessarily require the plaintext to be longer than ...
CCM mode (counter with cipher block chaining message authentication code; counter with CBC-MAC) is a mode of operation for cryptographic block ciphers. It is an authenticated encryption algorithm designed to provide both authentication and confidentiality. CCM mode is only defined for block ciphers with a block length of 128 bits. [1] [2]
Offset codebook mode (OCB mode) is an authenticated encryption mode of operation for cryptographic block ciphers. [ 1 ] [ 2 ] OCB mode was designed by Phillip Rogaway , who credits Mihir Bellare , John Black , and Ted Krovetz with assistance and comments on the designs.
The extra block sizes were not adopted by the AES standard. Many block ciphers, such as RC5, support a variable block size. The Luby-Rackoff construction and the Outerbridge construction can both increase the effective block size of a cipher. Joan Daemen's 3-Way and BaseKing have unusual block sizes of 96 and 192 bits, respectively.