Summary
Data-origin authentication
- ensure that a message truly originates from the claimed sender
- critical for communication security and detecting forgery
Entity authentication
Concept
Authentication
- assuring that the communicating entity, or origin of the information, is the one that it claims to be
- authenticity implies integrity
the latter is true for #cs2107, but there are varying definitions for authenticity and integerity
Data-origin
- authentic message: one whose origin is verifiable
- threats:
- message forgery (attacker injects data)
- replay attacks (attacker resends valid but old messages)
- techniques:
- cryptographic signatures (asymmetric)
- message Authentication Codes (MAC, symmetric)
- sequence numbers/timestamps to prevent replay