Koninklijke Philips Corporation N.v.

Civolution B.v.

Priv Id B.v.

Minne Van Der Veen

Alphons Antonius Maria Lambertus Bruekers

Antonius Adrianus Cornelis Maria Kalker

Jaap Andre Haitsma

Thomas Andreas Maria Kevenaar

Antonius Hermanus Maria Akkermans

Aweke Negash Lemma

Franciscus Maria Joannes Willems

Bart Johan Hendrikus Bouwman

Joseph Gerard Hubert Strous

A method for configuring a biometric template protected authentication system wherein the desired classification threshold is first selected to optimize the trade-off between a false accept (FAR) and a false non match or reject rate (FRR) of the system, and then an error correcting code (ECC) used in the authentication process is chosen such that the number of errors which can be corrected is equal to or greater than the selected classification threshold. During authentication, the number of errors in a first codeword derived from biometric data associated with a physical object is determined and used in the decision process to accept or reject authentication.

Defining classification thresholds in template protection systems

The invention provides a method for authenticating a physical object (OBJ) using a first helper data (W) and a first control value (V) associated with a reference object. The method comprises a step to generate a first property set (S) using a noise compensating mapping (NCM) on information derived from the first helper data (W) and a metric data (Y) associated with the physical object, and a step to establish a sufficient match between the physical object and the reference object using the first property set (S) and the first control value (V). The method further comprises a step to generate an update data (WUPD) for updating the first helper data (W) using the first helper data (W), the first property set (S) and the metric data (Y). Also provided is a client terminal configured to carry out the method.

Template renewal in helper data systems

The invention relates to a method of authentication of a physical object and an apparatus applying said method. The method uses a helper data (W) and a control value (V) associated with a reference object to generate a first property set (C) using the helper data (W) and a metric (Y) associated with the physical object. It further comprises a step to generate a second property set (S) using a noise compensating mapping (NCM) on the first property set (C), as well as a step to establish a sufficient match between the physical object and the reference object using the second property set (S) and the first control value (V). The method is characterized by a step that generates an error measure (ERR) by quantifying the noise removed by the noise compensating mapping (NCM) using the first property set (C) and information derived from the noise compensating mapping (NCM). Error measure (ERR) is subsequently used for generating an authentication decision (D). Also provided is an apparatus configured to carry out the method.

Shaping classification boundaries in template protection systems

There is described a system () for processing an input signal () to generate a corresponding encoded output signal (). The system () includes a plurality of quantizing devices () coupled in series, the system (being configured in operation to reduce tandem quantization noise arising therein by:

Method of reducing quantization noise

Disclosed is a method of adjusting a supplementary data signal (wm(n)) to be embedded in an information signal (x(n)), for example an audio signal. The method comprises the steps of determining () a position where a predetermined property of the information signal exceeds a predetermined threshold, e.g. an attack position, and suppressing () the supplementary data signal in a predetermined neighbourhood of the determined position.

Embedding supplementary data in an information signal

Disclosed is a method of adjusting a supplementary data signal (wm(n)) to be embedded in an information signal (x(n)), for example an audio signal. The method comprises the steps of determining () a relative magnitude (g(n)) of a first property function (Mx(n)) of the information signal averaged over a region of a predetermined size and a second property function (M(n)) of the supplementary data signal averaged over said region; and adjusting () the supplementary data signal according to the determined relative magnitude.

The invention relates to a system for detecting a watermark using informed detection. A first signal potentially having a watermark embedded is received () as is a second signal corresponding to the original signal. The signals are segmented () into symbol segments. For each symbol segment a first characteristic is determined () for a first section and a second characteristic is determined () for a second section in response to the first and second signals in those sections. Specifically, ratios between average envelopes are determined. Thus, the first and second characteristic is indicative of the variations of the envelope during a watermark symbol. A watermark symbol estimate is determined () from the first and second characteristic. A sequence of estimated watermark symbols is compared to reference watermark symbols and the presence of a watermark symbol is determined () depending on the comparison. The invention is particularly suitable for improved detection of a multiplicative watermark.

Method and apparatus for detecting a watermark in a signal

System for performing telemetric measurements, comprising a plurality of mobile communication devices (), each communication device () being provided with at least one sensor () and a sensor control section () for performing measurements, a cellular communication network structure for the mobile communication devices, a server provided with communication means for receiving measurement data from the plurality of mobile communication devices (), and for sending measurement instructions to respective sensor control sections () of the mobile communication devices () wherein the sensor control sections () are programmable by the server.

System and method for performing telemetric measurements

methods of embedding and detecting a watermark in an information signal (x(n), y'(n)) which are robust against sampling rate conversions of the watermarked signal (y(n)) adapts frame lengths used by an embedder and the detector, respectively, so as to preserve a constant ratio between the respective sampling rate and frame length. The frame lengths may be calculated from a greatest common divisor of a set of sampling rates providing watermarks which are robust against sampling rate conversions between any sampling rates of the set of sampling rates.

Watermarking

The invention relates to a method of checking the correct operation of a signal transformation wherein a input signal is transformed into an output signal. The method comprises: deriving a first robust feature from the input signal; deriving a second robust feature from the output signal; comparing said first and second robust features; in case of sufficient sumilarity, concluding a correct operation of said signal transformation, and in case of insufficient sumilarity, concluding a false operation of said signal transformation. In a special embodiment, the method is applied wherein the first robust feature is embedded in the input signal through watermark technology, the thus obtained signal being transmitted to a receiver so as to retrieve an output signal corresponding to said input signal.

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Eindhoven, Netherlands

Minne Van Der Veen