A future-adaptive password scheme

摘要: Many authentication schemes depend on secret passwords. Unfortunately, the length and randomness of user-chosen passwords remain fixed over time. In contrast, hardware improvements constantly give attackers increasing computational power. As a result, password such as traditional UNIX user-authentication system are failing with time. This paper discusses ways building systems in which security keeps up speeds. We formalize properties desirable good system, show that cost any secure scheme must increase improves. present two algorithms adaptable cost--eksblowfish, block cipher purposefully expensive key schedule, bcrypt, related hash function. Failing major breakthrough complexity theory, these should allow password-based to adapt well into future.