The protocol opens with A communicating in clear to AS his own claimed identity and the identity of the desired correspondent, B, together with A's nonce identifier for this transaction, I_(A1). (Nonce means used only once.)

The Greeks also used an instrument called a rhombus, or witches' wheel. As the wheel spun round, it was thought that influence was gained over certain people or circumstances.

2001: In addition to stimulating the srteries to constrict, angiotensin also acts on the kidneys to suppress urine production, and acts on the brain to stimulate thirst and drinking behaviour. — Leslie Iversen, Drugs: A Very Short Introduction (Oxford 2001, p. 43)

I had a busful of fifth-grade students expecting a field trip.