Patent ID: 7873835

Claim:
A method of restricting access to a device, comprising: obtaining a passphrase for a user; obtaining access credentials for the user; obtaining a PIN value for the user; obtaining time/date data indicative of a date and time; one-way encrypting at least the access credentials, the time/date data and the PIN using a secret key provided with the device, wherein the secret key is generated independently of the access credentials and the PIN value for the user and is provided on the device prior to an access attempt by the user, wherein the passphrase is generated using the secret key and is generated externally to the device and prior to the access attempt by the user, and wherein the secret key is not directly accessible to the user based on the passphrase used to access the device in the access attempt; allowing access to the device if the result of one-way encrypting equals the passphrase; and denying access to the device if the result of one-way encrypting does not equal the passphrase.