2. An authentication protocol
- A challenge-response protocol based on the use of nonces
- Step1: Client Alice sends her identity and a freshly generated challenge (nonce) to Server Bob.
- Step2: Bob sends a ticket with his name, his response to Alice’s challenge (signature on the nonce), and a challenge of his own.
- Step3: Alice signs Bob’s nonce and includes the signature with her service request.
- Optimization using incremented nonces
3. {Alice, SigA(NB), request}