Tjhai
Cen Jung Tjhai, Devon GB
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20130094649 | PUBLIC KEY CRYPTOSYSTEM BASED ON GOPPA CODES AND PUF BASED RANDOM GENERATION - 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. | 04-18-2013 |
Cen Jung Tjhai, Playmouth GB
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20080294967 | Incremental Redundancy Coding System - 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. | 11-27-2008 |
Cen Jung Tjhai, Plymouth GB
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20090019334 | ERROR CORRECTION SYSTEM USING CONCATENATED CODES - 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. | 01-15-2009 |
20090249162 | ERROR CORRECTION SYSTEM USING THE DISCRETEFOURIER TRANSFORM - A system of determining unknown symbols of an error correcting code using the Discrete Fourier Transform (DFT) with arithmetic corresponding to the number field of the error correcting code, including complex numbers. Encoder and decoder configurations are described. Parallel generation of independent parity check equations, simultaneous solution of unknown symbols generating, or regenerating a codeword of the error correcting code. | 10-01-2009 |
20110305231 | Communication System for Short Range Reliable Information Transfer - The invention is concerned with providing a wireless transmitting and receiving system such that an information stream may be exchanged in both directions over a relatively short range and with a high level of robustness and tolerance to propagation conditions. Several applications are envisaged, such as a hand-off internet radio system in which the user equipment may resemble a traditional domestic analogue radio set combining features of robustness and high audio quality but able to play audio streams from internet radio stations, talking books and encoded music together with a transmitting command system. Other envisaged applications include robust tracking and location systems, range extension of wireless systems such as WiFi, Bluetooth and a robust video streaming system. The unlicensed low power Instrument Scientific Medical (ISM) and Short Range Devices (SRD) frequency bands are well suited to be used by the invention. The invention matches the baseband bandwidth and number of baseband channels to the propagation conditions of the wireless link, provides low peak to average spectral power density and automatic error correction without synchronisation dependency. These features make the invention extremely tolerant to the high variability in propagation conditions which are commonly experienced in indoor wireless reception. wireless hand-off transmitting and receiving system such that a radio station streamed over the internet may be received wirelessly using a receiver which to the user may resemble a traditional domestic analogue radio set combining features of robustness and high audio quality. A return communication channel provides an automatic means of adapting to changing propagation conditions of the wireless link as well as providing the user with the ability to control the information being received. | 12-15-2011 |
20120121084 | PUBLIC KEY ENCRYPTION SYSTEM USING ERROR CORRECTING CODES - This invention provides improved security and improved throughput of the McEliece public key encryption system and reduces the public key size. Even though the public key is reduced, in some embodiments of the invention the ensemble of cryptograms produced is identical to the ensemble of cryptograms produced by the original system for a given Goppa code, and the same private key. It is possible using this invention that the encrypted message, 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. Other embodiments of the invention use a shortened error correcting code allowing the length of the generated cryptogram to match exactly the available transmission or storage media such as is the case of RFID and packet based radio applications. | 05-17-2012 |
Cen Jung Tjhai, London GB
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20130283035 | DIGITAL FILE AUTHENTICATION USING BIOMETRICS - 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. | 10-24-2013 |
Phin Tjhai, Chatswood AU
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20130232831 | METHOD, DEVICE AND APPARATUS FOR DELIVERING PROMOTION AND ADVERTISING - The present invention relates to a method and system for delivering messages, such as advertising messages. Printed labels are provided on drinks container lids, such as takeaway coffee container lids. Providing printed labels has the advantage that the lid does not need to be changed to provide a different message. Only the printed label has to be changed. | 09-12-2013 |
Phin Tjhai, New South Wales AU
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20110153398 | Device, Method and System for Facilitating a Transaction - The present invention relates to a device, method and system for facilitating a transaction. In particular, it relates to a drinks container lid on which is provided transaction data, such as a machine readable code. The transaction data may be entered into a mobile communications device, such as a mobile phone, by key entry or by scanning. It then may facilitate a transaction. In one embodiment, the transaction data is a program which causes the mobile device to communicate with a remote transaction processing system to implement a transaction. | 06-23-2011 |
Phin Tjhai, Roseville AU
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20130346169 | Device, Method and System for Facilitating a Transaction - The present invention relates to a device, method and system for facilitating a transaction. In particular, it relates to a drinks container lid on which is provided transaction data, such as a machine readable code. The transaction data may be entered into a mobile communications device, such as a mobile phone, by key entry or by scanning. It then may facilitate a transaction. In one embodiment, the transaction data is a programme which causes the mobile device to communicate with a remote transaction processing system to implement a transaction. | 12-26-2013 |