Authentification of a user across communicaqtion sessions

A method for facilitating the re-authentication of a user using a client computer, against a server computer, comprising the steps of: a) establishing a first communication session between the client computer and the server computer, and generate a key (110) ; b) receive confidential information from the client computer; the method characterized by c) while generating an identifier identifying the first communication session (120) d) encrypt confidential information with the key, to create encrypted confidential information (115), and associate the identifier with the encrypted confidential information ( 125); e) storing confidential information encrypted on the server computer; f) transmitting the key and the identifier to the client computer (135); g) delete key on the server computer (145); h) establishing a second communication session after deleting the key on the server computer; i) receive confidential information associated with encrypted identifier from the client computer, during the second communication session key; j) use the identifier to locate the encrypted confidential information before using the key to decrypt the encrypted confidential information; k) use the key on the server computer to decrypt the encrypted confidential information.