SIMPLE AND EFFICIENT ONE-PASS AUTHENTICATED ENCRYPTION SCHEME

The present invention provides encryption schemes and apparatus, which are more efficient than the existing single pass authenticated encryption schemes, while providing the same level of security. The initial vectors, which are an essential part of these schemes, are chosen in an incremental and safe fashion. This also leads to an incremental method for generating the pair-wise differentially uniform sequences or XOR-universal sequences which are another essential part of such schemes. The incrementality of the generation of these sequences extends to even across different plain-text messages being encrypted, leading to substantial savings in time to encrypt. A further step of encryption is shown to be redundant and leads to savings over earlier schemes. Another embodiment describes splitting the plain-text blocks into two sets, and using the block-cipher in encrypt mode on one set and the block-cipher in decrypt mode on the other set, leading to beneficial hardware solutions.