Recognizing the inherent difficulty to prove id -- it's advisable to employ several independent IDs especially for crucial situations where misidentification is very damaging.
An ID previously exchanged over a secure channel
Data reflecting past exchanges between the parties
Data reasonably expected to be possessed by the identity prover.
Multi-parametric identification is burdensome -- security and convenience must be well balanced
* Version CE-H6703 (SERVER) Crypto Academy