A Fast Encryption Mode for Block Cipher with Integrity Authentication

Most important things of secure communications are integrity and confidentiality. However, seldom cipher mode could achieve these two goals simultaneously. So, in this paper, a novel cipher mode is proposed to solve this scheme. The newly proposed mode is based on a previous work PCBC, which has the vulnerability that it permits the modification of swapping two ciphertext, which could pass the integrity authentication. In our algorithm, by adding another XOR operation with a counter to the mode, we successfully solve the vulnerability of PCBC, so we named it C-PCBC. In addition, our algorithm could be more efficient than another modification M-PCBC, thus it will be very useful in the case where confidentiality and integrity are both needed.