Abstract: The present invention relates to a system (600) and method for sharing multiple session keys between low-power devices (701) and more advanced devices (702). A polynomial algorithm with a certain number of parameters is used. A large number of parameters are fixed for the low-power devices (701) and a small number of parameters are fixed for the more powerful devices (702).

Abstract: Information signals such as grayscale images or audio signals are represented as a sequence of PCM signal samples. To embed auxiliary data in the least significant bits of the signal, the samples are slightly distorted. There is a so-termed “rate-distortion function” (20) which gives the largest embedding rate R given a certain distortion level D. It appears that the efficiency of prior art embedding schemes such as LSB replacement (21,22) can be improved. The invention discloses such embedding schemes (23,24). According to the invention, the signal is divided into groups of L (L>1) signal samples (x). For each group of signal samples, a vector of least significant portions (x mod n) of the signal samples is created. For n=2, the vector comprises the least significant bit of each signal sample. The syndrome of said vector (as defined in the field of error detection and correction) represents the embedded data.

Abstract: A method of embedding an additional layer of error correction into an error correcting code, wherein information is encoded into code words of said code over a first Galois field and wherein a number of code words are arranged in the columns of a code block comprising a user data sub-block and a parity data sub-block, provides an additional layer of error correction that can be easily implemented without losing compatibility improving the error correction capabilities. The method includes the steps of: encoding the rows of at least the user data sub-block separately or in groups using a horizontal error correcting code over a second Galois field larger than the first Galois field to obtain horizontal parities, and embedding the horizontal parities as additional layer in the error correcting code.

Abstract: A method of embedding an additional layer of error correction into an error correcting code, where information is encoded into code words that are arranged in columns of a code block. The method includes reducing the length of each row of the code block by adding row symbols together according to a predetermined adding rule resulting in a reduced code block; encoding the shortened rows of the reduced code block using a horizontal error correcting code to obtain horizontal parities; and embedding the horizontal parities as additional layer in the error correcting code.

Abstract: The invention relates to a method of storing a number of data bits of a secondary channel (30) in the frame of a main channel (20) and to a method of decoding a stream of bits relating to a secondary channel (30) embedded in the frames of a main channel (20) into a stream of data bits (62). In order to enable a certain synchronization and to guarantee a fixed amount of storage capacity in the secondary channel as well as to be able to correct deletions or insertions of bits in the secondary channel it is proposed according to the invention to form a secondary frame (11) having a fixed number of frame bits, to fill a fixed part of the secondary frame (11) with data bits (113), an end-bit (114) set to a first bit-value and, if necessary, with filling bits (115) set to a second bit-value, to encode the secondary frame (11) producing encoded data bits (113) and parity bits (112), which are finally embedded in the frame of the main channel (20).

Abstract: A method of selecting a generator matrix (G) for encoding information words (m) including information symbols (m1, m2, mk) into codewords (c) of a code (C) provides an enhanced error correction capability if at least one information symbol (m1, m2, m3) is known a priori to a decoder decoding received, possibly mutilated codewords (r). In order to design a code of which the correction power is enhanced if some information symbols are known to the decoder prior to decoding, the generator matrix (G) is selected such that the minimum Hamming distance of at least one subcode (C?) of the code (C) is larger than the minimum Hamming distance of the code (C), and that a subcode generator matrix (G?) of the at least one subcode (C?) is derived from the generator matrix (G) of the code (C) by omitting the at least one row from the generator matrix (G) corresponding to the at least one a priori known information symbol (m1, m2, m3).

Abstract: The invention relates to a method of selecting a generator matrix (G) for encoding information words (m) comprising information symbols (m1, m2, . . . , mk) into codewords (c) of a code (C) for providing an enhanced error correction capability if at least one information symbol (m1, m2, m3) is known a priori to a decoder decoding received, possibly mutilated codewords (r). The invention relates further to a method of encoding information words (m) into codewords (c) and to a method of decoding possibly mutilated codewords (r).

Abstract: The invention relates to a method and device for encoding information words and a method and device for decoding as well as a storage medium for storing and a signal comprising such encoded information words. In order to improve the properties of a burst-indicator subcode it is proposed to encode the bits of a burst-indicator subcode byte into different channel words. Thus, these bits are spread over an entire frame of encoded data improving burst error detecting and correcting properties.

Abstract: Described is a transmission system for transmitting a multilevel signal (xk) from a transmitter (10) to a receiver (20). The transmitter (10) comprises a mapper (16) for mapping an input signal (ik) according to a signal constellation onto the multilevel signal (xk). The receiver (20) comprises a demapper (22) for demapping the received multilevel signal (yk) according to the signal constellation. The signal constellation comprises a number of signal points with corresponding labels. The signal constellation is constructed such that Da>Df, with Da being the minimum of the Euclidean distances between all pairs of signal points whose corresponding labels differ in a single position, and with Df being the minimum of the Euclidean distances between all pairs of signal points. By using this signal constellation a significantly lower error rate can be achieved than by using a prior-art signal constellation.

Abstract: The invention relates to a method for generating a serial bitstream comprising information for synchronizing the serial bitstream internally and/or to another serial bitstream and/or for determining the position in the serial bitstream wherein a fixed code pattern is embedded in the serial bitstream. In order to retrieve a synchronization information or to determine the position in the serial bitstream very fast after the start of reading the serial bitstream and at any time during reading the serial bitstream it is provided according to the invention that the code pattern is periodically repeated in the serial bitstream and that any sequence of a fixed number of successive bits of the code pattern forms a unique code word allowing for synchronization and/or position determination, even under the occurrence of bit errors.

Abstract: The invention relates to a method of storing a number of data bits of a secondary channel (30) in the frame of a main channel (20) and to a method of decoding a stream of bits relating to a secondary channel (30) embedded in the frames of a main channel (20) into a stream of data bits (62). In order to enable a certain synchronization and to guarantee a fixed amount of storage capacity in the secondary channel as well as to be able to correct deletions or insertions of bits in the secondary channel it is proposed according to the invention to form a secondary frame (11) having a fixed number of frame bits, to fill a fixed part of the secondary frame (11) with data bits (113), an end-bit (114) set to a first bit-value and, if necessary, with filling bits (115) set to a second bit-value, to encode the secondary frame (11) producing encoded data bits (113) and parity bits (112), which are finally embedded in the frame of the main channel (20).

Abstract: The invention relates to an apparatus for reading out information from an information carrier, the information including at least a first signal of at least partly encrypted content, to an apparatus for storing such information as well as to corresponding methods. The invention proposes a realisation of the Content Scrambling System (CSS) rule: CSS encrypted content on a recordable disc should be refused. In order to be able to use a wobbled disc for distinguishing ROM-discs from recordable discs, it is required that in the content on “new” discs there will be a “wobble-trigger”. This trigger has the following requirements: —it should be easily detectable from looking just at the content, —it should not be easily removable by a hacker, —it should not affect content preparation.

Abstract: The invention relates to a method for encoding a stream of bits of a signal relating to a binary source into a stream of bits of a signal relating to a binary channel, the binary source comprising a main source and a secondary source, the main source being encoded in a main channel by multi-level coding and the secondary source being encoded in a secondary channel, the secondary channel being embedded in the main channel in order to form the binary channel, wherein the secondary channel is divided in at least a first section comprising user data and a second section comprising non user data.