Cryptography Questions Medium
The Electronic Codebook with Cipher Block Chaining (ECB-CBC) mode is a combination of two 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 encryption key. This means that if the same plaintext block appears multiple times, it will be encrypted into the same ciphertext block. ECB mode does not provide any form of error propagation, making it vulnerable to certain attacks, such as frequency analysis.
On the other hand, Cipher Block Chaining (CBC) mode is a more secure encryption mode. In CBC mode, each plaintext block is XORed with the previous ciphertext block before encryption. This introduces a dependency between blocks, as the ciphertext of each block is dependent on the previous block's ciphertext. Additionally, an Initialization Vector (IV) is used to XOR with the first plaintext block. CBC mode provides error propagation, meaning that any changes or errors in the ciphertext will affect the decryption of subsequent blocks.
The ECB-CBC mode combines these two modes to enhance security. It divides the plaintext into blocks and encrypts each block using ECB mode. However, before encrypting each block, it XORs the plaintext block with the previous ciphertext block. This introduces the dependency and error propagation of CBC mode while still utilizing the simplicity of ECB mode for individual block encryption.
Overall, the ECB-CBC mode provides a balance between security and efficiency, making it a commonly used encryption mode in various cryptographic applications.