Block ciphers converts plain text data into blocks usual sizes of each block are 64 bits, 128 bits, and 256 bits then it applies encryption on each block and makes cipher-text.
The algorithm modes which are used in block cipher are: ECB (Electronic Code Book) and CBC (Cipher Block Chaining)
Most modern symmetric encryption algorithms are block ciphers.
e.g. -> AES, 3DES, DES, IDEA, Blowfish, Serpent, Twofish
Advantages:
- Block ciphers uses both confusion and diffusion
- Immunity to tampering: difficult to insert symbols without detection.
Disadvantages:
- Slowness of encryption: an entire block must be accumulated before encryption / decryption can begin.
- Error propagation: An error in one symbol may corrupt the entire block.
- In block cipher, reverse encrypted text is hard.
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