Patent ID: 11930353
Assignee: TISSOT SA
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method for monitoring or tracking between mobile devices of a same group of mobile devices, comprising:
the mobile devices broadcasting messages in general broadcast mode over a radio interface in compliance with a short-range digital communication protocol, the messages being able to be received by all other mobile devices in a vicinity and capable of communicating according to said protocol, the messages comprising encrypted data obtained by encryption of at least one identifier of an emitter device and a seed intended for single use or having a short period of validity, the encrypted data only being able to be decrypted by a limited group of devices possessing a decryption key; and
the mobile devices receiving the messages broadcast by the other mobile devices and decrypting the messages intended for a group to which the mobile devices belong,
wherein, if the protocol for short-range digital communication provides that the message comprises a field for an address of the emitter device, the field is filled with a randomised address that does not identify the address of the emitter device intended for single use or having a short period of use.