Method and apparatus for encoding and decoding data transmitted to an authentication token

摘要

Methods and apparatus for encoding and decoding data transmitted acoustically and/or optically to strong authentication tokens to generate dynamic security values are disclosed. The tokens may also include a selection mechanism to select either an acoustical or an optical input interface to receive data. A communication interface may be provided to communicate with a removable security device such as a smart card and the token may be adapted to generate dynamic security values in cooperation with the removable security device.

主权项

1. A handheld strong authentication token for generating dynamic security values comprising:
a data storage component for storing data; at least one of an acoustical input interface for acoustically receiving input data and an optical input interface for optically receiving input data, the acoustical interface, if present, comprising a microphone and a demodulation circuit connected to the microphone adapted to demodulate an acoustical signal received by the microphone, and the optical input interface, if present, comprising at least one or more optical detectors for receiving an optical signal; and a data processing component connected to the at least one of the acoustical input interface and the optical input interface, the data processing component adapted to recover input data transmitted in the acoustical or optical signal received by the at least one of an acoustical input interface and optical input interface, to process the recovered input data, and to generate the dynamic security values; wherein the data processing component is further adapted to decode a message comprising at least two data blocks and comprising at least the input data and transmitted in the acoustical or optical signal received by the at least one of the acoustical input interface and the optical input interface by:
detecting the boundaries of a received data block within the message;detecting whether the received data block has already been buffered in the data storage component;buffering the received data block in the data storage component if it had not yet been buffered;detecting whether the received data block comprises an ordinary payload block comprising at least a part of the input data or an extra redundancy block;determining whether the complete input data can be recovered from the buffered ordinary payload blocks;determining whether any missing input data can be calculated from the buffered ordinary payload blocks and the buffered extra redundancy blocks;calculating at least part of the missing input data from the contents of at least some of the buffered ordinary payload blocks and the contents of at least some of the buffered extra redundancy blocks;recovering the complete input data from the buffered ordinary payload blocks or from the buffered ordinary payload blocks and the calculated missing input data.