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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) state key laboratory of information security Graduate School of Chinese Academy of Sciences Beijing 100049 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 state key laboratory of information security Graduate University of Chinese Academy of Sciences Beijing 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

Threshold quantum secure direct communication without entanglement

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science china(Physics,Mechanics & Astronomy) 2008年第2期51卷 176-183页

作者： YANG YuGuang1,3 & WEN QiaoYan2 1 College of Computer science and Technology, beijing university of Technology, beijing 100022, china 2 School of science, beijing university of Posts and Telecommunications, beijing 100876, china 3.state key laboratory of information security (graduate School of chinese academy of sciences), beijing 100049, china College of Computer science and Technology Beijing University of Technology Beijing China state key laboratory of information security (graduate School of chinese academy of sciences) Beijing China School of science Beijing University of Posts and Telecommunications Beijing China

For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir's secret sharing scheme, the sender makes n shares, S1, …, Sn of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he en-codes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially per-form the corresponding unitary operations on the single photon sequence and ob-tain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology.

关键词： quantum secure direct communication threshold secure direct communication quantum secret sharing

Analysis of a kind of quantum cryptographic schemes based on secret sharing

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science china(Physics,Mechanics & Astronomy) 2009年第9期52卷 1313-1316页

作者： ZHANG XingLan1 & JI DongYao2 1 College of Computer science and Technology, beijing university of Technology, beijing 100124, china 2 state key laboratory of information security, graduate university of chinese academy of sciences, beijing 100049, china College of Computer science and Technology Beijing University of Technology Beijing China state key laboratory of information security Graduate University of Chinese Academy of Sciences Beijing China

Recently, Yang et al. proposed a kind of quantum cryptographic schemes based on secret sharing. The main idea is drawn from the case, where any n participants who share a secret K can co-operate as K does. This process can be applied to encryption, authentication, signature and so on. Unfortunately, since there is no identity authentication of the share's holder, these schemes inherit the limitation of secret sharing in practice. If some participants do not follow the protocol, the protocol would be a failure at last. Moreover, these schemes encounter another serious attack. Any two participants can co-operate to defeat the schemes by sending different shares to the parties unknown to the distributor of the secret K, such that these parties can execute the protocol as well. The attack proves that it is not enough for quantum cryptographic schemes that only the secret key is secure.

关键词： quantum identity authentication quantum secure direct communication quantum signature secret sharing

Joint source channel VL coding/decoding for deep space communication networks based on a space trellis

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science china(information sciences) 2011年第9期54卷 1883-1894页

作者： WU WeiRen 1,TU Juan 2,TU GuoFang 1,GAO ShaoShuai 1 & ZHANG Can 1,3 1 School of information science and Engineering,graduate university of chinese academy of sciences,beijing 100049,china 2 beijing Institute of Electronic System Engineering,china Aerospace science & Industry Corp.,beijing 100854,china 3.state key laboratory of information security,graduate university of chinese academy of science,beijing 100049,china School of information science and Engineering Graduate University of Chinese Academy of Sciences Beijing China beijing Institute of Electronic System Engineering China Aerospace Science & Industry Corp. Beijing China state key laboratory of information security Graduate University of Chinese Academy of Science Beijing China

This paper presents joint source channel variable length (VL) coding/decoding based on a space *** constructing a joint decoding plane trellis,better decoding performance can be achieved than by using the bit-level decoding ***,the plane trellis is complicated,which results in high decoding complexity for decoding VL turbo *** solve this problem,we construct a space trellis and design a low-complexity joint decoding algorithm with a variable length symbol-a posteriori probability (VLS-APP) algorithm in resource constrained deep space communication *** results show that the proposed approach reduces the decoding complexity by 10% compared with the plane trellis,and the gain of Eb/N0 is about 0.2 dB at SER=***,it provides substantial error protection for variable-length encoded image data.

关键词： joint coding/decoding VL turbo codes space trellis VLS-APP

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 China state key laboratory of Integrated Services Network Xidian University Xi’an China state key laboratory of information security Graduate University of Chinese Academy of Sciences Beijing China state key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 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 China state key laboratory of Integrated Services Network Xidian University Xi’an China state key laboratory of information security (graduate university of chinese academy of sciences) Beijing China state key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 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 College of Computer science and Technology Beijing University of Technology Beijing China state key laboratory of Integrated Services Network Xidian University Xi’an China state key laboratory of information security (graduate university of chinese academy of sciences) Beijing China state key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 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

Quasi-secure quantum dialogue using single photons

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science china(Physics,Mechanics & Astronomy) 2007年第5期50卷 558-562页

作者： YANG YuGuang1,2 & WEN QiaoYan31 College of Computer science and Technology, beijing university of Technology, beijing 100022, china 2 state key laboratory of information security, graduate university of the chinese academy of sciences, beijing 100049, china 3 School of science, beijing university of Posts and Telecommunications, beijing 100876, china College of Computer science and Technology Beijing University of Technology Beijing China state key laboratory of information security Graduate University of the Chinese Academy of Sciences Beijing China School of science Beijing University of Posts and Telecommunications Beijing China

A quasi-secure quantum dialogue protocol using single photons was proposed. Different from the previous entanglement-based protocols, the present protocol uses batches of single photons which run back and forth between the two parties. A round run for each photon makes the two parties each obtain a classical bit of information. So the efficiency of information transmission can be increased. The present scheme is practical and well within the present-day technology.

关键词： quantum dialogue, single photon, quantum secure direct communication