Patent ID: 9537845
Date: 2017-01-03
CPC Classifications: G06F,H04L

Claim:
1. A method comprising: storing in a memory of a first processing device information relating to one or more historical events visible to the first processing device and a second processing device, the one or more historical events being associated with at least a first authentication session between the first processing device and the second processing device; and in a second authentication session between the first processing device and the second processing device: wherein the stored information comprises at least one of: wherein the indicator permits the second processing device to determine authenticity of the first processing device by verifying the indicator using information stored at the second processing device relating to the one or more historical events, the information stored at the second processing device relating to the one or more historical events being stored at the second processing device prior to receipt of the indicator by the second processing device; wherein the indicator comprises a single bit value indicating whether the given historical event occurred during a first interval within a second interval, the second interval being longer than and containing the first interval; wherein the first interval and the second interval have respective predefined lengths; and wherein the second interval ends at a current time.