Block Cipher Authenticated-Encryption Modes Of Operation

Block cipher can be standardized easily and implemented efficiently in software and hardware at high speed. So it is becoming an extensive application in the fields of computer communications and information security. The research of mode always goes with the development of block cipher.1. Dissertation discusses three kinds of block cipher modes of operation: encryption mode, authentication mode and authentication-encryption mode. The current research status and the development trend of the block cipher are summarized. The concept and some secure properties of three modes are described. At the same time, some schemes are briefly introduced.2. When a block cipher is viewed as a pseudorandom function, the block cipher may be subject to the birthday attack. In order to resist the birthday attack, we should build secure pseudorandom function (PRF) from pseudorandom permutation (PRP) .Based on PRF, we can acquire block cipher modes of operation with beyond the birthday bound. We propose a block cipher mode of operation ECTR (Extended CTR), which has higher efficiency than that of M. Bellare's scheme, and higher security than that of T. Iwata's CENC.3. When a message is transmitted in the network and both its privacy and authenticity need to be protected, there may be additional information, that travelalongside the cipher text and must get authenticated with it. This is an authenticated-encryption with associated-data (AEAD) problem. Based on block cipher modes of operation with beyond the birthday bound, we can acquire AEAD schemes with beyond the birthday bound. First, an AEAD scheme CHM (CENC with Hash-based MAC) is reviewed. Then we combine CENC with MFH (Multilinear Field Hash family of function) to propose AEAD scheme PCHM (Parallel CHM) .We also prove the security of PCHM, which is also beyond the birthday bound security.