Patent ID: 7069439

Claim:
Computing apparatus comprising: memory means storing the instructions of a secure process and an authentication process; processing means arranged to control the operation of the computing apparatus including by executing the secure process and the authentication process; user interface means arranged to receive user input and return to the user information generated by the processing means in response to the user input; and interface means for receiving a removable primary token and communicating with the token, the token comprising a body supporting: a token interface for communicating with the interface means; a token processor; and token memory storing token data including identity information for identifying the token and auxiliary token information identifying one or more authorised auxiliary tokens, wherein the processing means is arranged to receive the identity information and the auxiliary token information from the primary token, authenticate the token using the authentication process and, if the token is successfully authenticated, permit a user to interact with the secure process via the user interface means, and wherein the processing means is arranged to repeatedly authenticate the primary token and cause the computing platform to suspend interaction between the secure process and the user if authentication is not possible as a result of the removal of the primary token unless the primary token is replaced by an authorised auxiliary token identified by said auxiliary token information.