A new convolutionally coded direct sequence (DS) CDMA system is proposed. The outputs of a convolutional encoder modulate multiple band-limited DS-CDMA waveforms. The receiver detects and combines signals for the desi...A new convolutionally coded direct sequence (DS) CDMA system is proposed. The outputs of a convolutional encoder modulate multiple band-limited DS-CDMA waveforms. The receiver detects and combines signals for the desired user and feeds a soft-decision Viterbi decoder. The performance of this system is compared to that of a convolutionally coded single carrier DS CDMA system with a Rake receiver. At roughly equivalent receiver complexity, results will demonstrate superior performance of the coded multicarrier system.展开更多
CLEFIA(named after the French word "Clef" meaning "Key") is an efficient,highly secure block cipher proposed by SONY Corporation in the 14 th International Workshop on Fast Software Encryption(FSE-...CLEFIA(named after the French word "Clef" meaning "Key") is an efficient,highly secure block cipher proposed by SONY Corporation in the 14 th International Workshop on Fast Software Encryption(FSE-2007) and many cryptanalyses have been used to analyze it.According to the property of CLEFIA,a new technique Sandwich-Boomerang cryptanalysis is used on it.An 8-round Sandwich-Boomerang distinguisher of CLEFIA is constructed using the best differential characteristic of CLEFIA.And then,based on the distinguisher,an attack against 10-round CLEFIA is proposed.The number of chosen plaintexts required is 2^(119)(or 2^(120)) and the time complexity is 2^(120)(or 2^(121)).Compared with a 7-round impossible Boomerang distinguisher presented by Choy in the 4th International Workshop on Security(IWSEC-2009),the differential characteristics used in the attack are all the best ones,so it is believed that the attack is the best result that the Boomerang attacks can get on CLEFIA at present.展开更多
文摘A new convolutionally coded direct sequence (DS) CDMA system is proposed. The outputs of a convolutional encoder modulate multiple band-limited DS-CDMA waveforms. The receiver detects and combines signals for the desired user and feeds a soft-decision Viterbi decoder. The performance of this system is compared to that of a convolutionally coded single carrier DS CDMA system with a Rake receiver. At roughly equivalent receiver complexity, results will demonstrate superior performance of the coded multicarrier system.
基金Supported by the National Science Foundation of China(No.60973161)the Doctoral Fund of Ministry of Education of China(No.200806140010)the National High Technology Research and Development Program of China(No.2009AA01Z422)
文摘CLEFIA(named after the French word "Clef" meaning "Key") is an efficient,highly secure block cipher proposed by SONY Corporation in the 14 th International Workshop on Fast Software Encryption(FSE-2007) and many cryptanalyses have been used to analyze it.According to the property of CLEFIA,a new technique Sandwich-Boomerang cryptanalysis is used on it.An 8-round Sandwich-Boomerang distinguisher of CLEFIA is constructed using the best differential characteristic of CLEFIA.And then,based on the distinguisher,an attack against 10-round CLEFIA is proposed.The number of chosen plaintexts required is 2^(119)(or 2^(120)) and the time complexity is 2^(120)(or 2^(121)).Compared with a 7-round impossible Boomerang distinguisher presented by Choy in the 4th International Workshop on Security(IWSEC-2009),the differential characteristics used in the attack are all the best ones,so it is believed that the attack is the best result that the Boomerang attacks can get on CLEFIA at present.
