A method and system for authenticating access to a storage area network (SAN) is disclosed in which a password is retrieved from a first copy of a password table in response to an access (login) request, the first copy of the password table residing on a switch and corresponding to a switch port. The password is used to retrieve a response from the first copy of the password table. The response is encrypted according to a first copy of an encryption key stored on the switch. The encrypted password is then sent to the node requesting access to the SAN, where it is decrypted according to a second copy of the encryption key residing on the node. The decrypted password is used to retrieve a response from a second copy of the password table residing on the node. The response is encrypted according to the second copy of the encryption key and sent back to the switch port. The response received from the node is then compared with the response determined from the first copy of the password table. Access to the SAN is permitted if the two responses match and denied otherwise. The method further includes a mechanism for generating codes based on hardware serial ID numbers (or other unique values) and comparing the serial ID numbers against previously stored codes to determine if the hardware serial numbers have changed and allowing or denying access to the SAN based upon that determination.