Cryptography Questions Medium
Cipher Block Chaining with Cipher Feedback and Propagating Cipher Block Chaining (CBC-CFB-PCBC) mode is a combination of three different modes of operation used in cryptography.
1. Cipher Block Chaining (CBC): In CBC mode, each plaintext block is XORed with the previous ciphertext block before encryption. This ensures that even if two plaintext blocks are identical, the corresponding ciphertext blocks will be different. CBC mode provides confidentiality and integrity.
2. Cipher Feedback (CFB): In CFB mode, the previous ciphertext block is encrypted and then XORed with the plaintext block to produce the ciphertext. This mode allows encryption of individual bits or bytes, making it suitable for streaming data. CFB mode provides confidentiality but does not provide integrity.
3. Propagating Cipher Block Chaining (PCBC): In PCBC mode, the XOR of the previous plaintext and ciphertext blocks is XORed with the current plaintext block before encryption. This mode provides diffusion of both plaintext and ciphertext errors, making it more resilient against tampering. PCBC mode provides confidentiality and integrity.
By combining these three modes, CBC-CFB-PCBC mode provides a strong level of security and integrity for encrypted data. It combines the benefits of confidentiality, integrity, and error diffusion, making it suitable for various cryptographic applications.