Patent ID: 9332430
Filing Date: 2016-05-03
CPC Classification: H04W

Claim Text:
1. A method of identifying and authenticating a radio tag when implemented by a radio reader, said tag forming part of a set of tags in a radio range of the reader and having selected a time slot from a set of available time slots, the method comprising: a step of the reader sending a query message comprising the set of available time slots; a step of the reader receiving during the selected time slot, a reply message from the tag that selected the time slot, said reply message including a random value selected by the tag, wherein the tag stores authentication coupons and the reply from the tag received by the reader during the time slot contains, as a random value selected by the tag, a value that is a function of one of said coupons, a step of the reader sending an acknowledgment message to said tag, the acknowledgment message being established as a function of the random value and including a challenge selected by the reader; and a step of the reader receiving an identification message from the tag, the identification message including identification information and an authentication reply calculated from the challenge.