| 摘要 |
The AIS (Automatic Identification System) is a system of communication between vessels, for example fishing vessels, which makes it possible to limit collisions between these vessels and which allows surveillance of the maritime traffic in view of the coast by virtue of coastal stations which listen to the communications. The collecting of these data by satellite allows maritime surveillance far from coasts and verification of the data transmitted by analysis of the signal received. The maritime surveillance authorities are desirous that the data, collected by satellite, relating for example to the position of the vessels in their territorial waters not be broadcast globally. Indeed, this would allow a user, by listening to the satellite, to ascertain the AIS messages exchanged far from these coasts. The AIS messages contain the position of the transmitting vessel, as well as its identifier, its direction, etc. The invention consists in implementing an encryption of the data that have been sent back down, based on the content of these data. The encryption of the data also allows the authorities to provide the AIS data as a service, possibly a pay-for service. |
