Protocol cassettes implement the functionality to carry out online commerce protocols. Gates are authentication methods. All communication with a cassette takes place through its gate. For example, the protocol cassette gives the ticket it received from the operation cassette to the JCC Role Manager, which checks that the ticket has not been altered since it was first loaded. If the security check passes, the cassette is given a permit.
Permits are objects returned by the gate.
For example, if the ticket has not been altered, the JCC framework stamps the ticket and passes it back to the protocol cassette's gate. To summarize, a cassette is signed with a role, which gets it a ticket, which gives the cassette a permit to do something. The JCC framework manages the interoperations between the operation, protocol, and instrument cassettes with tickets, gates, and permits. The short example for this series describes how to create the operation, protocol, and instrument cassettes for a simple purchase transaction. A purchase transaction might be initiated when a web store shopper chooses an item and selects the Pay button on a merchant server.