In recent years, many people use their office or home PC for their work and store the sensitive information, at the same time mobile computing has enjoyed a Persistent tremendous rise in popularity. There are various authentication techniques being used like password, log off system, Biometric techniques. Biometrics suffers from several usability problems. In distributed system, there is problem of hacking of confidential information. Physical security is a major problem for pc. The loss of laptop may lead to the exposure of credit card numbers, passwords, and client data.