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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 ...
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]
In cryptography, a cipher block chaining message authentication code (CBC-MAC) is a technique for constructing a message authentication code (MAC) from a block cipher.The message is encrypted with some block cipher algorithm in cipher block chaining (CBC) mode to create a chain of blocks such that each block depends on the proper encryption of the previous block.
A block cipher uses blocks as an unvarying transformation. Even a secure block cipher is suitable for the encryption of only a single block of data at a time, using a fixed key. A multitude of modes of operation have been designed to allow their repeated use in a secure way to achieve the security goals of confidentiality and authenticity.
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 ...
Counter Mode Cipher Block Chaining Message Authentication Code Protocol (Counter Mode CBC-MAC Protocol) or CCM mode Protocol (CCMP) is an authenticated encryption protocol designed for Wireless LAN products that implements the standards of the IEEE 802.11i amendment to the original IEEE 802.11 standard.
Example: Consider a scenario where a legitimate party called Alice encrypts messages using the cipher-block chaining mode. Consider further that there is an adversary called Eve that can observe these encryptions and is able to forward plaintext messages to Alice for encryption (in other words, Eve is capable of a chosen-plaintext attack ).
In principle any block-oriented block cipher mode of operation can be used, but stream-cipher-like modes can already be applied to messages of arbitrary length without padding, so they do not benefit from this technique. The common modes of operation that are coupled with ciphertext stealing are Electronic Codebook (ECB) and Cipher Block ...