Computer Security is an important issue now a days because these are used everywhere to store and process the sensitive information. Millions of transactions occur through internet on daily basis and these transactions are to be completed without being exposed to third party. Username and passwords are required to protect the sanctity of the initiating systems. Username can be easily known and passwords can be easily guessed. As the passwords are simple, they are vulnerable to attacks like phishing attacks and brute force attacks etc.

Thus a better way to strengthen the password is to combine the passwords with biometrics comprises of behavioral or psychological biometrics. Keystroke dynamics is one of the behavioral biometric techniques, which is cheaper and does not require any additional piece of hardware. The main focus of this paper is to provide an imminent survey of keystroke dynamics based biometrics methods, metrics and various approaches as well as challenges and future directions.