In this paper a new approach for
combining biometric authentication and digital watermarking is presented. A
digital audio watermark method is used to embed metadata into the reference
data of biometric speaker recognition. Metadata in our context may consist of
feature template representations complementary to the speech modality, such as
iris codes or biometric hashes, ancillary information about the social,
cultural or biological context of the originator of the biometric data or
technical details of the sensor. We suggest a well-known watermark embedding
technique based on LSB (least significant bit) modulation for this purpose,
perform experiments based on a database taken from 33 subjects and 5 different
utterances and a known cepstrum based speaker recognition algorithm in
verification mode. The goal is to perform a first evaluation of the recognition
precision for our selected algorithm. The first tests show that the recognition
precision is not significantly deteriorated by the embedding of the information,
as in three out of five cases, no degradation was observed at all and in the
worst case the relative increase in false recognition was limited to 1%.