COUNT-BASED CHALLENGE-RESPONSE CREDENTIAL PAIRS FOR CLIENT/SERVER REQUEST VALIDATION

摘要

A server computer system programmed to generate a first challenge credential to the client computer, that corresponds to a first response credential in a first challenge-response credential pair; render first dynamic-credential instructions causing the client to generate the first response credential; send the first challenge credential and the first dynamic-credential instructions, but not the first response credential; receive a request that includes a first test-challenge credential and a first test-response credential; determine whether the first test-challenge credential and the first test-response credential are the first challenge-response credential pair; if the first test-response credential is the first response credential, determine that a count is associated with the first challenge-response credential pair, and determine whether the count satisfies a first threshold; if the count does not satisfy the first threshold, determine that the first request is not a replay request and assign a second count to the first challenge-response credential pair.