Password-Only Authenticated Three-Party Key Exchange Proven Secure against Insider Dictionary Attacks

Box 1

Experiment Exp₀:

Phase  1.   makes any oracle queries at will as many times as it wishes, except that:

  (1) is not allowed to ask the Test() query if the instance is unfresh.

  (2) is not allowed to ask the Reveal() query if it has already made a Test query to  

      or , where is the partner of .

Phase  2. Once decides that Phase is over, it outputs a bit as a guess on the hidden bit

    chosen by the Test oracle. is said to succeed if .