摘要:
This invention provides improved security of the McEliece Public Key encryption system adding features which make full use of random number generation for given message and cryptogram parameters. Different embodiments of the invention are described which enable the level of security to be traded-off against cryptogram size and complexity. Message vectors are encoded with a scrambled generator matrix, using matrix multiplication to form codeword vectors. Shortened corrupted codewords are generated by corrupting each codeword vector and omitting a predefined number of bits, whereby a cryptogram is formed from the shortened corrupted codewords. Measures are included to defeat attacks based on information set decoding. A number of different applications are given.
摘要:
The present disclosure includes systems and methods for providing instant messaging communication between users via a communication network. Instant messaging clients are executed at user devices of a first and second user. A data message is transmitted from the instant messaging client at the user device of the first user to the instant messaging client at the user device of the second user, the data message having a content portion and at least one associated attribute that is cryptographically generated. The cryptographic attribute plus any additional first user attributes irrefutably binds the ID of the first user to the message information content to form an irrevocable message. The availability of at least one user-selectable function by the instant messaging client at the user device of the second user is controllable, based on the at least one associated attribute.
摘要:
The present disclosure includes systems and methods for quorum-based data recovery, in which data is recovered provided at least a minimum number of quorum data portions are presented. In exemplary embodiments, a predetermined minimum number of versions of original data is received, and the original data is reconstructed from the received versions, wherein the original data cannot be reconstructed without loss unless a predetermined minimum number of versions is received. In other embodiments, erroneous or corrupted quorum data portions are detected and associated participants presenting said erroneous or corrupted quorum data portions are identified.
摘要:
This invention provides an error correction system whereby codes, including codes known to be optimum, may be concatenated together so that a longer code is produced which may be decoded by decoding the individual codes using any type of error correcting decoder including list decoders, Dorsch decoders in particular, and iterative decoders. The concatenated code consists of one or more codes having replicated codewords to which are added codewords from one or more other codes. The code construction is utilised in the receiver with a decoder that firstly decodes one or more individual codewords from a received vector. The detected codewords from this first decoding are used to undo the code concatenation within the received vector to allow the replicated codewords to be decoded. Examples of the performance benefits of the invention in comparison to the well known state of the art coding arrangement of LDPC codes, and turbo codes using iterative decoders are given for (256,128) and (512,256) codes.
摘要:
In packet digital communications using a two way communications medium such as wireless each received packet is subject to noise and/or interference which causes errors in some of the received symbols. A common method known as Incremental Redundancy (IR), Hybrid Automatic Repeat Request (HARQ) for corrects these transmission errors by using error detection in conjunction with transmission of additional redundant symbols forming a sequence of forward error correcting codes. Any residual errors are detected by means of a Cyclic Redundancy Check (CRC). The CRC symbols represent transmission overhead and degrade the throughput regardless of the quality of the transmission channel. This invention is concerned with providing error detection without the need for a CRC thereby improving the throughput. In a further embodiment of the invention for those systems that employ a CRC increased reliability of detection is provided which also leads to an improvement in throughput. It is shown that by adjustment of a simple threshold value, the overall packet error rate may be traded off against throughput in a flexible manner. A method of construction of a sequence of codes from a nested block code is described and an example is provided based on a nested block code of length 128. The associated performance graphs of the invention, both using and not using a CRC, for this sequence of codes are given showing the performance improvements of the invention compared to the standard arrangement using a CRC for the same sequence of error correcting codes.
摘要:
The present disclosure includes systems and methods for quorum-based data recovery, in which data is recovered provided at least a minimum number of quorum data portions are presented. In exemplary embodiments, a predetermined minimum number of versions of original data is received, and the original data is reconstructed from the received versions, wherein the original data cannot be reconstructed without loss unless a predetermined minimum number of versions is received. In other embodiments, erroneous or corrupted quorum data portions are detected and associated participants presenting said erroneous or corrupted quorum data portions are identified.
摘要:
A method and system are described for authenticating one or more digital files in which a feature, characteristic or a portion of the contents of said files is implanted into one or more biometric information files, which are electronically recorded and transmitted and in which the identity of the originator or a trusted third party and all or part of the feature, characteristic or a portion of the contents of said files is determined from said biometric information files.
摘要:
This invention provides a means of authenticating digital files without the need for a central trusted authority. A message digest of one or more digital files is calculated, preferably using a cryptographic hash function and all or part of the digest value is implanted into one or more biometric information files produced by the originator of the digital files or a trusted third party. The recipient of the digital files and biometric information files is able to determine all or part of the digest value from the biometric information files, check that this corresponds to the calculated message digest of one or more digital files as well as check the identity of the originator or trusted third party. In further embodiments the biometric information files contain all or part of a digital signature generated by the originator of the digital files or a trusted third party. The invention may be used in many applications including the distribution of public encryption keys.
摘要:
This invention provides improved security of the McEliece Public Key encryption system adding features which make full use of random number generation for given message and cryptogram parameters, using this invention the encrypted message (i.e. the cryptogram) is a truly random function, not a pseudo random function of the message so that even with the same message and the same public key, a different, unpredictable cryptogram is produced each time. With the knowledge of the private key, the random function may be determined from the cryptogram and the message decrypted. Different embodiments of the invention are described which enable the level of security to be traded-off against cryptogram size and complexity. A number of different applications are given.
摘要:
Methods and systems are described for binding a data transaction to a person's identity using biometrics. The method comprises the generation of data which includes information associated with a transaction, or an encrypted transaction, between a server and a client device associated with a user, generating authentication data providing an irrevocable binding of the information to biometric characteristics of the user, by capturing biometric input by the user of said authentication data or information associated with the transaction, wherein this information is implanted into the captured data. A predetermined minimum number of quorum portions may be generated from a portion of the data generated or processed by the method, wherein at least a predetermined minimum number of received quorum data portions are required to reconstruct the data portion.