摘要:
A system 100 for increasing data security comprises predetermined system data 104 to be protected. A cryptographic unit 108 is used for cryptographic processing of respective blocks of the content data in dependence on respective keys. A key provider 106 determines the respective key used for the processing of a respective block of the content data in dependence on a respective portion 112 of the predetermined system data 104, the portion not including all the predetermined system data, wherein different respective portions of the predetermined system data are selected for the respective blocks of content data. A server system 200 for increasing data security comprises an output 202 for providing processed content data 110 to a client system 100, the client system comprising predetermined system data 104 to be protected. The server system 200 also comprises a cryptographic unit 208 and a key provider 206.
摘要:
A system 100 for increasing data security comprises predetermined system data 104 to be protected. A cryptographic unit 108 is used for cryptographic processing of respective blocks of the content data in dependence on respective keys. A key provider 106 determines the respective key used for the processing of a respective block of the content data in dependence on a respective portion 112 of the predetermined system data 104, the portion not including all the predetermined system data, wherein different respective portions of the predetermined system data are selected for the respective blocks of content data. A server system 200 for increasing data security comprises an output 202 for providing processed content data 110 to a client system 100, the client system comprising predetermined system data 104 to be protected. The server system 200 also comprises a cryptographic unit 208 and a key provider 206.
摘要:
A system 100 for updating cryptographic key data 120 comprises a key input 106 for receiving sequential key updates 114; and a key data updater 108 for changing a portion (116) of the cryptographic key data in response to a received one of the sequential key updates (114), the portion not including all the cryptographic key data, wherein different respective portions of the cryptographic key data are selected for respective ones of the sequential key updates. The system further comprises a content input 104 for receiving content data 112 to be processed; and a cryptographic unit 110 for cryptographic processing of the content data in dependence on the key data to obtain processed content data 118. The content input is arranged for receiving a content data stream, successive portions of the content data stream being encrypted based on successive keys corresponding to the successive key updates.
摘要:
A cryptographic method is implemented in a white-box implementation thereof. The method comprises applying a plurality of transformations (802) each replacing an input word by an output word, and applying a diffusion operator (804) to a concatenation of a plurality of the output words for diffusing information represented by the output words among the output words. A key (806) to the cryptographic method comprises information representing the diffusion operator. The diffusion operator satisfies a property that a change of one bit in an input to the diffusion operator corresponds to a change of more than one bit in an output of the diffusion operator.
摘要:
A system for increasing a tamper resistance of a digital data processing unit, comprises a first unit (901) comprising processing means (906) for processing the received digital data in dependence on values looked up in at least one look-up table (916) based on values in the received digital data. The system further comprises a second unit (902) comprising means (912) for computing at least one value for inclusion in the digital data causing the first unit (901) to look up at least one predetermined value in the look-up table (916) when processing the digital data. It comprises an inserter (910) for including the at least one value in the digital data, and an output (908) for transmitting the digital data to the first unit.
摘要:
The invention relates to a solid state lighting strip (100) for mounting in or on a panel support element (210) of a modular panel system (200). The strip comprises a plurality of solid state lighting elements (110, 110′), a light extraction layer (120) and a glare reducing layer (130). The solid state lighting elements are arranged such that the light emitted by said elements is coupled into the glare reducing layer via the light extraction layer. The solid state lighting strip (100) can be used as part of alighting system, a panel support element (210) and a modular panel system (200).
摘要:
A method of protecting an integrity of a data processing system. The method comprises determining (902) a data string to be protected, an integrity of the data string being an indication of the integrity of the data processing system. Computing (904) a set of parameters representing a predetermined data processing function, using a redundancy in the set of parameters to incorporate the data string into a bit representation of the set of parameters. Enabling (906) the system to process data according to the set of parameters. The set of parameters represents at least part of a cryptographic algorithm including a cryptographic key. The set of parameters represents a network of look-up tables. The network of look-up tables comprises a plurality of look-up tables of a white-box implementation of a data processing algorithm. The data processing algorithm comprises a cryptographic algorithm.
摘要:
A white-box cryptographic system (600) is presented for performing a key-dependent cryptographic operation, such as AES. The system comprises a network of a plurality of look-up tables (640) arranged for collectively performing the cryptographic operation, the network being adapted for a particular cryptographic key. By sending a key substitute (664) which represents to the network a further cryptographic key a key translation unit can arrange the effect of the network on the cryptographic operation such that is adapted for a further cryptographic key. In this way the system can be updated to use the further key instead of the particular key.
摘要:
A method of protecting an integrity of a data processing system. The method comprises determining (902) a data string to be protected, an integrity of the data string being an indication of the integrity of the data processing system. Computing (904) a set of parameters representing a predetermined data processing function, using a redundancy in the set of parameters to incorporate the data string into a bit representation of the set of parameters. Enabling (906) the system to process data according to the set of parameters. The set of parameters represents at least part of a cryptographic algorithm including a cryptographic key. The set of parameters represents a network of look-up tables. The network of look-up tables comprises a plurality of look-up tables of a white-box implementation of a data processing algorithm. The data processing algorithm comprises a cryptographic algorithm.
摘要:
A white-box cryptographic system is presented wherein at least one of its internal values is represented using an input dependent encoding. The system comprises a network of a plurality of basic blocks arranged for collectively performing a cryptographic operation. An encoder is arranged for encoding output data of a first one of the plurality of basic blocks into an encoder-output according to a selected one of a plurality of encoding schemes, said selection depending on an input-message to the system. A compensator is arranged for recoding intermediate data to compensate for the effect of the encoding according to a selected one of a plurality of recoding schemes. Using variable encodings instead of fixed encodings complicates reverse engineering the white-box cryptographic system.