Computer Security

CIA triad

• Confidentiality: how do you prevent unauthorised personnel from viewing your information
• Integrity: How do you ensure that data is not compromised throughout its entire lifecycle
• Availability: Info is readily available at all times (not any different from availability in generic computing terms)

Nonce

Questions

• What is a nonce?
• What is a replay attack
• What is challenge response? Does a value c have to be sent and returned on every challenge?

A nonce is used to prevent a replay attack.

A replay attack occurs when you try to