Abstract: A method, system and computer program for protecting the password by limiting the password's validity to the user's active session. The present invention provides for password to automatically change for each session and only the user will be able to construct the valid password for the session. The user provides to the authentication system, a password pattern, embedding symbols in to a string. The embedded symbols are substituted by elements of parameters. The parameter elements and the symbols that represent them are defined by the authenticating system. The parameters contain either time driven or random string of characters and digits as elements. The user builds a password using the values of the elements in the session parameters and the user's password pattern's memory hint recalled from memory. The authenticating system generates the valid password for the session using the password pattern the user has provided.