Patent ID: 6510517
Filing Date: 2003-01-21
Classification: G06K,G06Q,G07F,G11C

Abstract:
A method of cryptological authentification in a scanning identification system having a base station, which supplies energy via the alternating field to a transponder connected to the object to be identified, the method comprising the following steps:the base station generates an inquiry signal; upon receiving the inquiry signal transmitted by the base station, the transponder responds with an identification number stored in its memory; the base station then encodes a first bit sequence it has generated by using a key bit sequence that is allocated to the identification number of the transponder, and transmits the second bit sequence obtained in this manner to the transponder; when the second bit sequence is received, the transponder generates a checking bit sequence from the second bit sequence, and, following the complete reception of the second bit sequence, transmits this checking bit sequence to the base station; the transponder reconstructs the first bit sequence from the second bit sequence and encodes it using the key bit sequence allocated to the transponder, and transmits the third bit sequence obtained in this manner to the base station; while the transponder is still encoding the second bit sequence to form the third bit sequence, the base station uses the checking bit sequence to verify whether an error has occurred in the transmission of the second bit sequence, and may abort the ongoing encoding in the transponder; and the base station verifies the validity of the received third bit sequence.