METHOD AND DEVICE FOR EMITTING MESSAGES FOR GUARANTEEING THE AUTHENTICITY OF A SYSTEM AND METHOD AND DEVICE FOR VERIFYING THE AUTHENTICITY OF SUCH A SYSTEM

摘要

The invention relates to a method for emitting messages in order to guarantee the authenticity of the system that emitted said messages. The method includes the following steps, namely: a step comprising the selection of a threshold value used in a threshold-based cryptographic scheme, which value is greater than or equal to 1; - a step comprising the generation of a set of partial information items, such that knowledge of a number i, greater than or equal to the threshold value K, of partial information items can be used to verify a signature of at least part of the messages; and a fourth step comprising the sending of each partial information item separately in a distinct message. The invention also relates to a device for emitting messages for guaranteeing the authenticity of the system that emitted the messages, as well as to a method and a device for verifying the authenticity of such a system. In particular, the invention is suitable for global satellite-based radiocommunication and radionavigation systems.