Design goals

1. Both data and command sequences must be integrity checked.
2. The integrity check must be performed transparently for the user.
3. The integrity check should give little transmission and computation overhead.
4. Based on secret keys negotiated using the authentication option.
5. Incoming data must not be accepted (sent to the NVT Printer Unit) before it has been integrity checked.
6. The communicating parties must be able to negotiate about what type of integrity information to use.
7. The parties must be able to start and stop using the integrity option.
8. Must be able to detect all modifications to the data stream.
9. Must not require the data stream to be encrypted.