A system and method for providing secure access to a computer system. An access device divides the password into multiple segments and places them in data packets. In one embodiment, an authentication server has multiple addresses, and each packet is sent to a different address. The server then reassembles the password. In another embodiment, when the server receives a password, the server sends an index value back to the access device, which then accesses the server on another address indicated by the index value. Alternatively, the password is sent to multiple addresses for the server, and the server determines whether any of the received packets have been altered. The multiple password packets may be forced to follow different paths to the server, thereby denying hackers the ability to intercept all of the password characters or determine the inter-packet timing factor. The system is effective against passive and active hackers, Trojans, and phishing techniques.