Method of producing a proof of presence or of operation of an entity in an identified zone for a duration greater than a given threshold and monitoring system

摘要

The invention relates to a method of producing a proof of presence of an entity in a zone for a duration greater than a presence threshold and an electronic monitoring system. The method comprises a step of successive sendings of messages generated from a secret. The secret can be reconstituted on the basis of a number of messages that is greater than or equal to a threshold. Each message is sent over a period whose duration is chosen in such a way that the product of the duration of the send period times the threshold is substantially equal to the presence threshold. The method comprises a step of comparing the secret and a secret candidate generated from the messages received by the entity. The proof is produced only if the secret and the secret candidate are equal. The invention also relates to an electronic monitoring system. In particular, the invention applies to the tracking of persons under conditional freedom or in a probationary situation, or else to the generation of proofs of reliability and of availability of devices.