Cryptography Questions Medium
The Electronic Codebook with Cipher Block Chaining and Propagating Cipher Block Chaining (ECB-CBC-PCBC) mode is a combination of encryption modes used in cryptography.
The Electronic Codebook (ECB) mode is a basic encryption mode where each block of plaintext is encrypted independently using the same key. This mode is simple and efficient but lacks security as identical plaintext blocks will result in identical ciphertext blocks.
Cipher Block Chaining (CBC) mode addresses the security issue of ECB by introducing feedback from the previous ciphertext block into the encryption process. Each plaintext block is XORed with the previous ciphertext block before encryption, adding randomness and making the encryption more secure.
Propagating Cipher Block Chaining (PCBC) mode further enhances the security of CBC by incorporating feedback from both the previous plaintext and ciphertext blocks. In PCBC, each plaintext block is XORed with the previous plaintext and ciphertext blocks before encryption, providing additional diffusion and making it harder for an attacker to deduce information.
The ECB-CBC-PCBC mode combines these three modes to provide a more secure encryption process. It starts with the ECB mode for the first block, then switches to CBC mode for subsequent blocks, and finally uses PCBC mode for the last block. This combination helps to achieve a higher level of security and randomness in the ciphertext.