System and individual device for participation in a broadcast program

System allowing individuals to participate, according to a predetermined scenario, in a broadcast program from a receiving set and, in association with a server, to certify by time logging participation in said program, comprising:

• a) a plurality of individual and independent electronic devices for participation, each associated with an individual participating in said program, each device for participation comprising at least:
• interface means for entry of at least one datum representative of said participation in said program and establishment of a certification link with said server,
• first storing means for storing said participation datum and said scenario,
• a clock, and
• first measuring means for measuring a first relative time elapsed between a) at least a first event of said scenario, chronologically correlated with said entry of a participation datum in the device and b) the establishment of said certification link with the server,
• b) means of broadcasting said program to receiving sets, and
• c) at least one server fitted with first terminals for the establishment of certification links with said participation devices, said server comprising second measuring means for measuring a second relative time elapsed between a) at least a second event of said program, chronologically correlated with an absolute deadline for entry of said participation datum and b) the establishment of said certification link,
• d) each device and/or the server comprising comparing means for comparing the first and second relative times measured in the device and the server and for conditionally certifying said participation as a function of an outcome of said comparison.