Reader and transponder to hide the applications supported by a reader and / or transponder, and corresponding method

Transponder (104) comprising a storage unit (106) having stored a number of different applications; and a processing unit (108) is adapted to generate, upon request of a reader (102) a response; and a transmission unit (110) adapted to send the response to said reader (102), characterized the transponder (104) by the fact that the answer is interpretable using a decoding scheme known by both the transponder (104) as the reader (102); and wherein the processing unit (108) is adapted to extend a name of an application by a random number and to encode the number ampliadocon one associated with said application to generate the response key.