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A formula on linear complexity of highest coordinate sequences from maximal periodic sequences over Galois rings

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Progress in Natural Science:Materials International 2006年第9期16卷 998-1001页

作者： HU Lei and SUN Nigang (state key laboratory of information security, Graduate School of Chinese Academy of Sciences, beijing 100049, china) [a]state key laboratory of information security Graduate School of Chinese Academy of Sciences Beijing China

Using a polynomial expression of the highest coordinate map, we deduce an exact formula on the linear complexity of the highest coordinate sequence derived from a maximal periodic sequence over an arbitrary Galois ring of characteristic p2 , where p is a prime. This generalizes the known result of Udaya and Siddiqi for the case that the Galois ring is Z4.

关键词： Galois ring highest coordinate sequence linear complexity.

Paillier's trapdoor function hides Θ(n) bits

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Science china(information Sciences) 2011年第9期54卷 1827-1836页

作者： SU Dong & Lü KeWei state key laboratory of information security,Graduate University of Chinese Academy of Sciences,beijing 100049,china 1. state key laboratory of information security Graduate University of Chinese Academy of Sciences Beijing 100049 China

In this paper,we re-examine the bit security of Paillier’s trapdoor *** show that given a random w=gcyN mod N2 ∈ZN2* the most significant bit of its class c is a hard-core predicate,under a standard assumption that is computing composite residuosity class is *** the simultaneous security,we prove that n number of the class c’s bits are simultaneously hard-core under the standard assumption,where n is the length of c.

关键词： Paillier’s trapdoor function hard-core predicate hard-core function simultaneous security most significant bit

Quantum threshold group signature

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Science china(Physics,Mechanics & Astronomy) 2008年第10期51卷 1505-1514页

作者： YANG YuGuang1,2,3 & WEN QiaoYan4 1 College of Computer Science and Technology, beijing University of Technology, beijing 100124, china 2 state key laboratory of Integrated Services Network, Xidian University, Xi’an 710071, china 3 state key laboratory of information security (Graduate University of Chinese Academy of Sciences), beijing 100049, china 4 state key laboratory of Networking and Switching Technology, beijing University of Posts and Tele-communications, beijing 100876, china College of Computer Science and Technology Beijing University of Technology Beijing 100124 China state key laboratory of Integrated Services Network Xidian University Xi’an 710071 China state key laboratory of information security Graduate University of Chinese Academy of Sciences Beijing 100049 China state key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

关键词： threshold quantum signature trusted party quantum cryptography

Threshold quantum secret sharing between multi-party and multi-party

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Science china(Physics,Mechanics & Astronomy) 2008年第9期51卷 1308-1315页

作者： YANG YuGuang1,2,3 & WEN QiaoYan4 1 College of Computer Science and Technology,beijing University of Technology,beijing 100124,china 2 state key laboratory of Integrated Services Network,Xidian University,Xi’an 710071,china 3 state key laboratory of information security (Graduate University of Chinese Academy of Sciences),beijing 100049,china 4 state key laboratory of Networking and Switching Technology,beijing University of Posts and Tele-communications,beijing 100876,china College of Computer Science and Technology Beijing University of Technology Beijing 100124 China state key laboratory of Integrated Services Network Xidian University Xi’an 710071 China state key laboratory of information security (Graduate University of Chinese Academy of Sciences) Beijing 100049 China state key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

A threshold quantum secret sharing (TQSS) scheme between multi-party and multi-party was proposed using a sequence of single photons,which is useful and efficient when the parties of communication are not all present. We described the process of this TQSS scheme and discussed its security. It was shown that entan-glement is not necessary for quantum secret sharing. Moreover,the theoretic effi-ciency was improved to approach 100% as almost all the instances can be used for generating the private key,and each photon can carry one bit of information. This protocol is feasible with the present-day technique.

关键词： threshold quantum secret sharing quantum cryptography single photon multi-party and multi-party

Threshold proxy quantum signature scheme with threshold shared verification

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Science china(Physics,Mechanics & Astronomy) 2008年第8期51卷 1079-1088页

作者： YANG YuGuang1,3,4 & WEN QiaoYan2 1 College of Computer Science and Technology,beijing University of Technology,beijing 100124,china 2 state key laboratory of Networking and Switching Technology,beijing University of Posts and Tele-communications,beijing 100876,china 3 state key laboratory of Integrated Services Network,Xidian University,Xi’an 710071,china 4 state key laboratory of information security(Graduate University of Chinese Academy of Sciences) ,beijing 100049,china 1. College of Computer Science and Technology Beijing University of Technology Beijing 100124 China 3. state key laboratory of Integrated Services Network Xidian University Xi’an 710071 China 4. state key laboratory of information security (Graduate University of Chinese Academy of Sciences) Beijing 100049 China 2. state key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

A threshold proxy quantum signature scheme with threshold shared verification is proposed. An original signer could authorize a group as its proxy signers. Then only t or more of n persons in the proxy group can generate the proxy signature on behalf of the original signer and any t-1 or fewer ones cannot do that. When the proxy signature needs to be verified,any t or more of n persons belonging to the verification group can verify the message and any t-1 or fewer ones cannot verify the validity of the proxy signature.

关键词： quantum signature threshold proxy quantum group signature threshold shared verification

SOME RESULTS ON GENERALIZED DIFFERENCE SETS

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Journal of Systems Science & Complexity 2008年第1期21卷 76-84页

作者： Xiwang CAO School of Mathematical Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, china state key Lab. of information security, beijing 100049, china. School of Mathematical Science Nanjing University of Aeronautics Astronautics Nanjing 210016 China state key Lab. of information security Beijing 100049 China

Sequences with ideal correlation functions have important applications in communications such as CDMA, FDMA, etc. It has been shown that difference sets can be used to construct such sequences. The author extends Pott and Bradley＇s method to a much broader case by proposing the concept of generalized difference sets. Some necessary conditions for the existence of generalized difference sets are established by means of some Diophantine equations. The author also provides an algorithm to determine the existence of generalized difference sets in the cyclic group Zv. Some examples are presented to illustrate that our method works.

关键词： Correlation functions diophantine equations generalized difference sets.

Refined Convergents to the Associated Continued Fractions for Binary Sequences

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Acta Mathematica Sinica,English Series 1994年第2期10卷 179-191页

作者： Dai Zongduo Zeng Kencheng state key laboratory of information security Academia Sinica beijing, 100039 china 1. state key laboratory of information security Academia Sinica 100039 Beijing China

The relation between continued fractions and Berlekamp’s algorithm was studied by some reseachers. The latter is an iterative procedure proposed for decoding BCH codes. However, there remains an unanswered question whether each of the iterative steps in the algorithm can be interpreted in terms of continued fractions. In this paper, we first introduce the so-called refined convergents to the continued fraction expansion of a binary sequence s, and then give a thorough answer to the question in the context of Massey’s linear feedback shift register synthesis algorithm which is equivalent to that of Berlekamp, and at last we prove that there exists a one- to-one correspondence between the n-th refined convergents and the length n segments.

关键词： Refined Convergents to the Associated Continued Fractions for Binary Sequences

Nondegenerative ML-sequences over ring Z/(2~e)

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Chinese Science Bulletin 1999年第17期44卷 1557-1561页

作者： YANG Junhui and ZHAI QibinInstitute of Software , Chinese Academy of Sciences , beijing 100080, china state key laboratory of information security , beijing 100080, china Chinese Acad Sci Inst Software Beijing 100080 Peoples R China state key Lab Informat Secur Beijing 100080 Peoples R China

The so-called quasi-period of an ML-sequence has been introduced. It is noted that an ML-sequence may degenerate in the sense that it has the quasi-period shorter than its period, and the problem of constructing the n... 详细信息

关键词： nondegenerate ML-sequence quasi-period.

Improved multi-pass fast correlation attacks with applications

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Science china(information Sciences) 2011年第8期54卷 1635-1644页

作者： ZHANG Bin & FENG DengGuo state key laboratory of information security,Institute of Software,Chinese Academy of Sciences,beijing 100190,china 1. state key laboratory of information security Institute of Software Chinese Academy of Sciences Beijing 100190 China

In this paper we propose two new algorithms for multi-pass fast correlation attacks on stream *** first algorithm aims at fast symbol-wise decoding in the circumstances that the noise is not very high and we have little resource for *** second algorithm deals with the practical decoding problem in the high noise and limited keystream *** new algorithms are applicable to arbitrary form LFSR and compare favorably to the previously known algorithms in the scenarios under *** applications,we demonstrate new key recovery attacks on one-level Bluetooth E0 and LILI-128,*** 2 37 -bit keystream and 2 28-byte memory,our attack against one-level E0 needs 2 35.1 *** 2 24-bit keystream and 2 24.5 -byte memory,our attack on LILI-128 has time complexity 2 70.6 operations.

关键词： stream cipher fast correlation attacks linear feedback shift register (LFSR) Bluetooth E0 LILI-128