Negative database authentication using SAT a like method

Negative database is a new concept of database environment By negative database secure nature it may be used as a user authentication in accessing computer systems in order to improve the security and then the privacy of these systems. All the authentication systems use positive database of password to identify authorized users. The negative database of passwords represents all strings that are not in the password database in binary representations using don´t care symbol to decrease negative database size. In this paper we proposed a new authentication methodology using negative database [1]. The novelty of this approach is that the difficulty to discover any individual password by using known cracking tools. Negative database methodology can filter illegal users (hackers, crackers, etc.). Thus, it can provide a reliable schema in authentication systems whether local or online. Regarding to the large data size generated by Negative database, we will develop a novel compression technique to avoid size drawback.