Abstract: Generating a cryptographic key, for example using a received external key. A system to generate a cryptographic key may include a first data store which may store an authorization key. A system may include a second data store which may store a secure key and/or a public key. A system may include an access controller, which may allow access to a secure key, for example to an access request which may be accompanied by a digital signature. A system may include a key generator, which may generate a private key, for example using a received external key, a stored authorization key and/or a mapping function. A system may include an access request signal generator which may generate a digital signature and/or which may transmit an access request, for example including a generated digital signature, to an access controller to retrieve a secure key.

Abstract: A process for generating a number representative of an analogue data source (ADS) in which during enrolment a distinctive characteristic of the ADS is measured to obtain physical data (PD). Part of the PD is used to generate a physical value (PV) representative of the ADS. An error correction algorithm (ECA) is applied to the PV to generate error correction data (ECD), which is transformed, using another part of the PD, to generate transform data. During subsequent regeneration of the PV, the distinctive characteristic is re-measured to generate a new set of PD, and a PV is generated using the same part of the PD physical data as was used during enrolment. ECD is generated by transforming the transform data, using the same part of the PD as was used to transform the ECD during enrolment. The ECA uses the regenerated ECD to correct errors in the PV representative of the ADS.

Abstract: A captioning system is provided for providing captions for audio and/or video presentations. The captioning system can be used to provide text captions or audio descriptions of a video presentation. A user device is provided for the captioning system having a receiver operable to receive the captions together with synchronization information and a caption output circuit which is operable to output the captions at the appropriate timings defined by the synchronization information. The user device is preferably a portable hand-held device such as a mobile telephone, PDA or the like.

Abstract: There is decribed an apparatus for generating a number from data originating from an analogue source, the apparatus comprising means for performing a set of the data and then processing, in accordance with stored processing instructions predetermined by a training process, the data to generate the number. During the training process, the sensitivity of the value of the generated number to variation in each of the measurement values is analyzed, and the process instructions are generated so that the processing of individual measurement values is modified to reduce this sensitivity. In this way, the repeatability of the generated number is improved.

Abstract: There is described a communication system in which data is received by and/or transmitted to a telecommunications apparatus using an acoustic data channel. In embodiments, the data is encoded within the audio track of a media broadcast or other public broadcast. The invention has particular, but not exclusive, relevance to a cellular communication system. There are also described acoustic position detection systems for determining the position of a telecommunications apparatus.

Abstract: There is described an authentication system in which during an enrolment process a distinctive characteristic of a subject being enrolled is measured to generate a reference number representative of the subject. Authentication data is then generated using the reference number, and the authentication data is stored for use in a subsequent verification process. During verification, the representative characteristic of the subject being verified is re-measured to generate a test number representative of the subject being verified and the authentication data during enrolment is retrieved. The authentication system then checks for equality between the test number and the reference number using the retrieved authentication data. If the test number and the reference number are equal, then the authenticity of the subject is verified, otherwise the authenticity is denied.

Abstract: There is described a communication system in which data is received by and/or transmitted to a telecommunications apparatus using an acoustic data channel. In embodiments, the data is encoded within the audio track of a media broadcast or other public broadcast. The invention has particular, but not exclusive, relevance to a cellular communication system. There are also described acoustic position detection systems for determining the position of a telecommunications apparatus.

Abstract: There is described a communication system in which data is received by and/or transmitted to a telecommunications apparatus using an acoustic data channel. In embodiments, the data is encoded within the audio track of a media broadcast or other public broadcast. The invention has particular, but not exclusive, relevance to a cellular communication system. There are also described acoustic position detection systems for determining the position of a telecommunications apparatus.

Abstract: A number of encoders for encoding a data signal within an audio signal are provided. In some of the encoders, the audio signal is separated into a tonal part, and a residual part, and the data signal is shaped based on the residual part. In other encoders, the data signal is separated into a tonal part and a residual part, and the data signal is combined with the audio signal independence upon the residual part. In other encoders, the rate at which the data is encoded within the audio signal is varied in dependence upon the audio signal. There are also described various decoders associated with the described encoders.

Abstract: There is described a number of encoders for encoding a data signal within an audio signal. In some of the encoders, the audio signal is separated into a tonal part and a residual part, and the data signal is shaped based on the residual part. In other encoders, the data signal is separated into a tonal part and a residual part, and the data signal is combined with the audio signal independence upon the residual part. In other encoders, the rate at which the data is encoded within the audio signal is varied in dependence upon the audio signal. There are also described various decoders associated with the described encoders.

Abstract: A position determining system in which a mobile tag having an unknown position is tracked in space over time. In use, the mobile tag either transmits or receives signals including a pair of tones at different frequencies from a number of base stations having known locations. The phase of each of the received signals is then measured and the measured phases are then passed to a processing unit which determines the position of the tag at the time of the transmission of the signals on the basis of the difference between the measured phases of the two tones. In one embodiment, this system is combined with a conventional phase-based position measurement which is derived from phase measurements of similar tones transmitted between the mobile tag and different base stations.

Abstract: A position determining system in which a mobile tag having an unknown position is tracked in space over time. In use, the mobile tag either transmits or receives signals including a pair of tones at different frequencies from a number of base stations having known locations. The phase of each of the received signals is then measured and the measured phases are then passed to a processing unit which determines the position of the tag at the time of the transmission of the signals on the basis of the difference between the measured phases of the two tones. In one embodiment, this system is combined with a conventional phase-based position measurement which is derived from phase measurements of similar tones transmitted between the mobile tag and different base stations.

Abstract: There is decribed an apparatus for generating a number from data originating from an analogue source, the apparatus comprising means for performing a set of the data and then processing, in accordance with stored processing instructions predetermined by a training process, the data to generate the number. During the training process, the sensitivity of the value of the generated number to variation in each of the measurement values is analysed, and the process instructions are generated so that the processing of individual measurement values is modified to reduce this sensitivity. In this way, the repeatability of the generated number is improved.

Abstract: There is described a communication system in which data is received by and/or transmitted to a telecomunications apparatus using an acoustic data channel. In embodiments, The data is encoded within the audio track of a media broadcast or other public broadcast. The invention has particular, but not exclusive, relevance to a cellular communication system. There are also described acoustic position detection systems for determining the position of a telecomunications apparatus.

Abstract: There is described an apparatus for generating a cryptographic key using data representative of an analogue source. The apparatus has a number generator which processes the data representative of the analogue source to generate an intermediate key, the intermediate key being a number, and a data store for storing a mapping key, the mapping key being a number predetermined to combine with the intermediate key in accordance with a monotonic mapping function to generate a desired cryptographic key. Preferably, the number generator processes the data representative of an analogue source in accordance with stored process data, determined by a training process, which indicates attributes of the data whose values are to be measured and adjustment data for adjusting the values to improve the repeatability of generation of the intermediate key.