Data origin authentication

Data origin authentication verifies source of data (provides assurance on identity of source of the received data)

Does not protect against modification or duplication of data (i.e. doesn’t provide integrity)

“connectionless”

Peer entity authentication

Verifies the identity of entity with which you’re communicating, usually at connection set-up (provides assurance on identity of entities connected)

Addresses masquerade and replay threats

It is “connection oriented”