检索结果-南通市图书馆

Refined Convergents to the Associated Continued Fractions for Binary Sequences

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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

On constant-round zero-knowledge proofs of knowledge for NP-relations

在线全文

学校读者我要写书评

暂无评论

Science china(information Sciences) 2010年第4期53卷 788-799页

作者： LI HongDa1*, XU HaiXia1, LI Bao1 & FENG DengGuo2 1state key laboratory of information security, Graduate University of Chinese Academy of Sciences, beijing 100049, china 2state key laboratory of information security, Institute of Software of Chinese Academy of Sciences, beijing 100080, china 1. state key laboratory of information security Graduate University of Chinese Academy of Sciences Beijing 100049 China2. State Key Laboratory of Information Security Institute of Software of Chinese Academy of Sciences Beijing 100080 China

This paper considers the existence of constant-round zero-knowledge proofs of knowledge for NP under standard assumptions. By introducing a new interactive proof model, we construct a 3-round zero-knowledge proof of knowledge system for the NP-relation under the assumption that factoring is intractable. Our construction not only shows the existence of constant-round zero-knowledge proofs of knowledge, but also gives a positive answer to the open problem of the existence of 3-round zero-knowledge proofs for NP.

关键词： zero-knowledge proof proof of knowledge constant-round NP-relation

Privilege Flow Oriented Intrusion Detection Based on Hidden Semi-MarkovModel

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2005年第1期10卷 137-141页

作者： ZHONG An-ming 1, JIA Chun-fu 1,21.College of information Technology and Sciences, Nankai University, Tianjin 300071,china 2.state key laboratory of information security, Institute of Software of Chinese Academy of Science, beijing 100039,china College of information Technology and Sciences Nankai University Tianjin 300071 China

A privilege flow oriented intrusion detection method based on HSMM (Hidden semi-Markov Model) is discussed. The privilege flow model and HSMM are incorporated in the implementation of an anomaly detection IDS (Intrusion Detection System). Using the dataset of DARPA 1998, our experiment results reveal good detection performance and acceptable computation cost.

关键词： key words intrusion detection privilege flow model HSMM

Black-box testing based on colorful taint analysis

在线全文

学校读者我要写书评

暂无评论

Science china(information Sciences) 2012年第1期55卷 171-183页

作者： CHEN Kai1,2,3,FENG DengGuo1,SU PuRui1&ZHANG YingJun1,2,3 1state key laboratory of information security,Institute of Software,Chinese Academy of Science,beijing 100190,china 2state key laboratory of information security,Graduate University of Chinese Academy of Sciences,beijing 100049,china 3National Engineering Research Center of information security,beijing 100190,china 1. state key laboratory of information security Institute of Software Chinese Academy of Science Beijing 100190 China2. State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China3. National Engineering Research Center of Information Security Beijing 100190 China

Software vulnerability detection is one of the most important methods for guaranteeing software *** main classes of methods can detect vulnerabilities in binary files:white-box testing and black-box *** former needs to construct and solve path constraints to detect *** has two main drawbacks:path exploding and complexity of *** latter often aimlessly exhausts various inputs to test binary *** paper combines both testing methods to detect vulnerabilities in binary *** analyzing the input elements that aect check condition corresponding to a certain check point,we can generate one class of inputs that get to the check point to increase fuzzing *** analyzing the relationship between guard conditions and check condition,the redundant check points are *** taint analysis method(CTAM)is proposed to compute guard conditions,which is more ecient than traditional taint analysis method(TTAM).We implemented a prototype and made several experiments on *** results showed that our method could increase the eciency of black-box testing.

关键词： software testing vulnerability detection dynamic testing black-box testing colorful taint analysis

Research on applying physical chaos generator to spacecraft information security

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2009年第5期52卷 1463-1470页

作者： ZHAO HePing state key laboratory of information security,Graduate University of Chinese Academy of Sciences,beijing 100049,china china Academy of Space Technology,beijing 100094,china state key laboratory of information security Graduate University of Chinese Academy of Sciences Beijing 100049 China china Academy of Space Technology Beijing 100094 China

The effectiveness of a short-length message extension method based on physical chaos generator was analyzed and the entropy of the extended message was calculated in this *** analysis demon-strated that with the mentioned method the entropy of short-length messages,which are repeatedly used in spacecraft data systems,is obviously increased,and the security of transmission is enhanced as *** paper also presented an improvement of the protocol for secret key agreement presented by *** and *** of depending on characteristics of communication channel,this method takes advantage of the random data produced by physical chaos generator to preset the initial parameters of the procedure on both sides of communication,so that the procedure and quantity of cipher key can be precisely *** method can be used to cipher key management of se-cure communication between long life-span spacecraft and ground system.

关键词： physical chaos generator spacecraft information security message extension cipher key management

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

在线全文

学校读者我要写书评

暂无评论

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.

Round-optimal zero-knowledge proofs of knowledge for NP

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(information Sciences) 2012年第11期55卷 2473-2484页

作者： LI HongDa1,FENG DengGuo2,LI Bao1 & XUE HaiXia1 1state key Lab of information security,Graduate University of Chinese Academy of Sciences,beijing 100049,china 2state key Lab of information security,Institute of software of Chinese Academy of Sciences,beijing 100080,china 1. state key Lab of information security Graduate University of Chinese Academy of Sciences Beijing 100049 China2. State Key Lab of Information Security Institute of software of Chinese Academy of Sciences Beijing 100080 China

It is well known that all the known black-box zero-knowledge proofs of knowledge for NP are *** there exit constant-round black-box zero-knowledge proofs of knowledge for all NP languages under certain standard assumptions is an open *** paper focuses on the problem and gives a positive answer by presenting two constructions of constant-round(black-box) zero-knowledge proofs of knowledge for the HC(hamiltonian cycle) *** the recent result of Katz,our second construction which relies on the existence of claw-free functions has optimal round complexity(5-round) assuming the polynomial hierarchy does not collapse.

关键词： zero-knowledge proofs proofs of knowledge black-box simulation constant-round

Quantum threshold group signature

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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.