Abstract: A device to apply a digital fingerprint to a digital signal comprises a means of intercepting or acquiring a signal, a storage element and a processor for executing computer implemented program code components in the storage element to effect the methods. The methods include transforming a plurality of signal samples onto a discrete orthonormal basis and ranking the transformed samples according to their magnitude. The n largest principal components of the ranked transformed samples are optionally permuted to generate a re-ordered set of principal components, which are then altered by a marking angle. The marked principal components and unmarked non-principal components are converted and combined and applying an inverse of the transform function to the combined principal and non-principal components to generate a fingerprinted digital signal. Methods to prepare the signal for marking, recover the digital fingerprint and verify the distributor and/or recipients of the signal are also disclosed.

Abstract: A device to apply a digital fingerprint to a digital signal comprises a means of intercepting or acquiring a signal, a storage element and a processor for executing computer implemented program code components in the storage element to effect the methods. The methods include transforming a plurality of signal samples onto a discrete orthonormal basis and ranking the transformed samples according to their magnitude. The n largest principal components of the ranked transformed samples are optionally permuted to generate a re-ordered set of principal components, which are then altered by a marking angle. The marked principal components and unmarked non-principal components are converted and combined and applying an inverse of the transform function to the combined principal and non-principal components to generate a fingerprinted digital signal. Methods to prepare the signal for marking, recover the digital fingerprint and verify the distributor and/or recipients of the signal are also disclosed.

Abstract: A device to apply a digital fingerprint to a digital signal comprises a means of intercepting or acquiring a signal, a storage element and a processor for executing computer implemented program code components in the storage element to effect the methods. The methods include transforming a plurality of signal samples onto a discrete orthonormal basis and ranking the transformed samples according to their magnitude. The n largest principal components of the ranked transformed samples are optionally permuted to generate a re-ordered set of principal components, which are then altered by a marking angle. The marked principal components and unmarked non-principal components are converted and combined and applying an inverse of the transform function to the combined principal and non-principal components to generate a fingerprinted digital signal. Methods to prepare the signal for marking, recover the digital fingerprint and verify the distributor and/or recipients of the signal are also disclosed.

Abstract: A device for modulating communication signals comprises a transceiver for receiving and transmitting the signal, a storage medium storing computer implemented programme code components to generate sequences and a processor in communication with the storage medium and transceiver. The processor executes computer implemented programme code components to generate a family of shift sequences or arrays using exponential, logarithmic or index functions and a polynomial or a rational function polynomial in i?p?1 for a finite field p of prime p. Multiple columns of the arrays are substituted with pseudo-noise sequences or other suitable good correlation sequences in a cyclic shift equal to the shift sequence for the respective column to generate a substituted array. The substituted array, or a sequence unfolded using the CRT from the array when the array dimensions are relatively prime, is applied to a carrier wave of the communication signal to generate a modulated communication signal.

Abstract: A device for applying or extracting a digital watermark of two or more dimensions and a method of applying or extracting the digital watermark. The digital watermark is generated by adding a suitable number of watermarking arrays. Each watermarking array is constructed by convolving a multi-periodic shift array having a correlation bounded by a constant (two or greater) with a balanced periodic substitution sequence.