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Website Penetration Testing

Block Ciphers

A block cipher its an encryption method that applies a effected algorithm with a symmetric key to encrypt a block of text rather than encrypting one bit at a time as use in stream ciphers. For instance, a common block cipher - AES, encrypts 128 bit blocks with a key of preset length of 128, 192 or it can be 256 bits.

Block cipher modes is to eliminate the chance of encrypting same blocks of text the same way. A Initialization vector (IV) can described as block of bits is also used by modes of operation that is use to ensure ciphertexts remain distinct even when same plaintext message is encrypted a number of times.