Tail-MAC: A Message Authentication Scheme for Stream Ciphers

Tail-MAC, A predecessor to the VMPC-MAC, algorithm for computing Message Authentication Codes for stream ciphers is described along with the analysis of its security. The proposed algorithm was designed to employ some of the data already computed by the underlying stream cipher in the purpose of minimizing the computational cost of the operations required by the MAC algorithm. The performed analyses indicate several problems with the security of the scheme and lead to a new design which described in a paper ”VMPC-MAC: A Stream Cipher Based Authenticated Encryption Scheme”. The new scheme solves all the problems found at a cost of some compromise in the performance.