Time Limited Code

A method of authenticating a token which has a time limited validity period, the method comprising:

• providing a system including a user terminal associated with a user, a server operatively coupled to the user terminal, and a scanner operatively coupled to the user terminal, wherein the scanner is adapted to store a secret key which is associated with a time period and which is shared with the server;
• the user operating the user terminal to generate a user request for issuance of a token and sending the user request to the server;
• the server receiving the user request and sending a customer token to a customer device and a modified token to the user terminal, wherein the modified token is a modified version of the customer token, and wherein the customer token is displayed on the customer device in the form of an optically scannable image;
• operating the scanner to scan the customer token displayed on the customer device;
• using the secret key to modify the customer token scanned from the customer device pertaining to a time period at which the customer token is scanned to produce a modified customer token, and sending the modified customer token to the user terminal;
• and
• at the user terminal, receiving the modified customer token and comparing the modified customer token to the modified token sent from the server to determine whether the modified customer token is valid.

A system for authenticating a token which has a time limited validity period, the system comprising:

• a user terminal associated with a user,
• a server, operatively coupled to the user terminal, and
• a scanner, operatively coupled to the user terminal, and adapted to store a secret key which is associated with a time period and which is shared with the server;
• wherein, in use:
• the user initiates a user request for issuance of a token;
• the server receives the user request and sends a customer token to a customer device and a modified token to the user terminal, wherein the modified token is a modified version of the customer token, and wherein the customer token is displayed on the customer device in the form of an optically scannable image;
• the scanner scans the customer token displayed on the customer device, uses the stored secret key to modify the customer token pertaining to a time period at which the customer token is scanned to produce a modified customer token, and sends the modified customer token to the user terminal;
• and
• the user terminal receives the modified token sent by the server, receives the modified customer token from the scanner, and compares the scanned modified customer token with the modified token to determine whether the modified customer token is valid.