Identity-based proxy signature enables an entity to delegate its signing rights to another entity in identity-based cryptosystem settings. However, few existing scheme has been proved secure in a formalized model, or ...Identity-based proxy signature enables an entity to delegate its signing rights to another entity in identity-based cryptosystem settings. However, few existing scheme has been proved secure in a formalized model, or acquired optimized performance. To achieve the goals of both proven security and high efficiency, this paper proposed an efficient identity-based proxy signature scheme. The scheme is constructed from bilinear pairing and proved secure in the random oracle model, using the oracle replay attack technique introduced by Pointehval and Stern. The analysis shows that the scheme needs less computation costs and has a shorter signature than the other schemes.展开更多
We developed a novel absolute multi-pole encoder structure to improve the resolution of the multi-pole encoder, realize absolute output and reduce the manufacturing cost of the encoder. The structure includes two ring...We developed a novel absolute multi-pole encoder structure to improve the resolution of the multi-pole encoder, realize absolute output and reduce the manufacturing cost of the encoder. The structure includes two ring alnicos defined as index track and sub-division track, respectively. The index track is magnetized based on the improved gray code, with linear halls placed around the track evenly. The outputs of linear halls show the region the rotor belongs to. The sub-division track is magnetized to N-S-N-S (north-south-north-south), and the number of N-S pole pairs is determined by the index track. Three linear hall sensors with an air-gap of 2 mm are used to translate the magnetic filed to voltage signals. The relative offset in a single N-S is obtained through look-up. The magnetic encoder is calibrated using a higher-resolution incremental optical encoder. The pulse output from the optical encoder and hall signals from the magnetic encoder are sampled at the same time and transmitted to a computer, and the relation between them is calculated, and stored in the FLASH of MCU (micro controller unit) for look-up. In the working state, the absolute angle is derived by looking-up with hall signals. The structure is simple and the manufacturing cost is very low and suitable for mass production.展开更多
Signcryption, which was introduced by ZHEN~ is a cryptographic primitive that fulfils the functions of both digital signature and encryption and guarantees confidentiality, integrity and non-repudiation in a more effi...Signcryption, which was introduced by ZHEN~ is a cryptographic primitive that fulfils the functions of both digital signature and encryption and guarantees confidentiality, integrity and non-repudiation in a more effi- cient way. Certificateless signcryption and pro- xy signcryption in identity-based cryptography were proposed for different applications. Most of these schemes are constructed by bilinear pairings from elliptic curves. However, some schemes were recently presented without pai- rings. In this paper, we present a certificateless proxy identity-based signcryption scheme with- out bilinear pairings, which is efficient and secure.展开更多
In asynchronous Multiple-Input-Multiple-Output Orthogonal Frequency Division Multiplexing(MIMO-OFDM) over the selective Rayleigh fading channel,the performance of the existing linear detection algorithms improves slow...In asynchronous Multiple-Input-Multiple-Output Orthogonal Frequency Division Multiplexing(MIMO-OFDM) over the selective Rayleigh fading channel,the performance of the existing linear detection algorithms improves slowly as the Signal Noise Ratio (SNR) increases.To improve the performance of asynchronous MIMO-OFDM,a low complexity iterative detection algorithm based on linear precoding is proposed in this paper.At the transmitter,the transmitted signals are spread by precoding matrix to achieve the space-frequency diversity gain,and low complexity iterative Interference Cancellation(IC) algorithm is used at the receiver,which relieves the error propagation by the precoding matrix.The performance improvement is verified by simulations.Under the condition of 4 transmitting antennas and 4 receiving antennas at the BER of 10-4,about 6 dB gain is obtained by using our proposed algorithm compared with traditional algorithm.展开更多
To solve the problems of the AMR-WB+(Extended Adaptive Multi-Rate-WideBand) semi-open-loop coding mode selection algorithm,features for ACELP(Algebraic Code Excited Linear Prediction) and TCX(Transform Coded eXcitatio...To solve the problems of the AMR-WB+(Extended Adaptive Multi-Rate-WideBand) semi-open-loop coding mode selection algorithm,features for ACELP(Algebraic Code Excited Linear Prediction) and TCX(Transform Coded eXcitation) classification are investigated.11 classifying features in the AMR-WB+ codec are selected and 2 novel classifying features,i.e.,EFM(Energy Flatness Measurement) and stdEFM(standard deviation of EFM),are proposed.Consequently,a novel semi-open-loop mode selection algorithm based on EFM and selected AMR-WB+ features is proposed.The results of classifying test and listening test show that the performance of the novel algorithm is much better than that of the AMR-WB+ semi-open-loop coding mode selection algorithm.展开更多
Error codes induced by M-ary modulation and modulation selection in network-based control systems are studied.It is the first time the issue of error codes induced by M-ary modulation is addressed in control field.In ...Error codes induced by M-ary modulation and modulation selection in network-based control systems are studied.It is the first time the issue of error codes induced by M-ary modulation is addressed in control field.In network-based control systems,error codes induced by noisy channel can significantly decrease the quality of control.To solve this problem,the network-based control system with delay and noisy channel is firstly modeled as an asynchronous dynamic system(ADS).Secondly,conditions of packet with error codes(PEC)loss rate by using M-ary modulation are obtained based on dynamic output feedback scheme.Thirdly,more importantly,the selection principle of M-ary modulation is proposed according to the measured signal-to-noise ratio(SNR)and conditions of PEC loss rate.Finally,system stability is analyzed and controller is designed through Lyapunov function and linear matrix inequality(LMI)scheme,and numerical simulations are made to demonstrate the effectiveness of the proposed scheme.展开更多
In this paper, we study λ-constacyclic codes over the ring R = Z4 + uZ4, where u^2 = 0, for λ= 1 + 3u and 3 + u. We introduce two new Gray maps from R to Z4^4 and show that the Gray images of λ-constacyclic cod...In this paper, we study λ-constacyclic codes over the ring R = Z4 + uZ4, where u^2 = 0, for λ= 1 + 3u and 3 + u. We introduce two new Gray maps from R to Z4^4 and show that the Gray images of λ-constacyclic codes over R are quasi-cyclic over Z4. Moreover, we present many examples of λ-constacyclic codes over R whose Z4-images have better parameters than the currently best-known linear codes over Z4.展开更多
Any linear code can be used to construct a linear secret sharing scheme.In this paper,it is shown how to decide optimal linear codes(i.e.,with the biggest information rate)realizing a given access structure over finit...Any linear code can be used to construct a linear secret sharing scheme.In this paper,it is shown how to decide optimal linear codes(i.e.,with the biggest information rate)realizing a given access structure over finite fields.It amounts to solving a system of quadratic equations constructed from the given access structure and the corresponding adversary structure.The system becomes a linear system for binary codes.An algorithm is also given for finding the adversary structure for any given access structure.展开更多
Constacyclic codes are an important class of linear codes in coding theory.Many optimal linear codes are directly derived from constacyclic codes.In this paper,(1 — uv)-constacyclic codes over the local ring F_p + uF...Constacyclic codes are an important class of linear codes in coding theory.Many optimal linear codes are directly derived from constacyclic codes.In this paper,(1 — uv)-constacyclic codes over the local ring F_p + uF_p + vF_p + uvF_p are studied.It is proved that the image of a(1 — uv)-constacyclic code of length n over F_p + uF_p + vF_p + uvF_p under a Gray map is a distance invariant quasi-cyclic code of index p2 and length p^3n over F_p.Several examples of optimal linear codes over F_p from(1 — uv)-constacyclic codes over F_p + uF_p + vF_p + uvF_p are given.展开更多
This paper proposes a general method to construct 1-resilient Boolean functions by modifying the Tu-Deng and Tang-Carlet-Tang functions. Cryptographic properties such as algebraic degree, nonlinearity and algebraic im...This paper proposes a general method to construct 1-resilient Boolean functions by modifying the Tu-Deng and Tang-Carlet-Tang functions. Cryptographic properties such as algebraic degree, nonlinearity and algebraic immunity are also considered. A sufficient condition of the modified func- tions with optimal algebraic degree in terms of the Siegenthaler bound is proposed. The authors obtain a lower bound on the nonlinearity of the Tang-Carlet-Tang functions, which is slightly better than the known result. If the authors do not break the "continuity" of the support and zero sets, the functions constructed in this paper have suboptimal algebraic immunity. Finally, four specific classes of 1-resilient Boolean functions constructed from this construction and with the mentioned good cryptographic properties are proposed. Experimental results show that there are many 1-resilient Boolean functions have higher nonlinearities than known l-resilient functions modified by Tu-Deng and Tang- Carlet-Tang functions.展开更多
Finite projective geometry method is effectively used to study the relative generalized Hamming weights of 4-dimensional linear codes, which are divided into 9 classes in order to get much more information about the r...Finite projective geometry method is effectively used to study the relative generalized Hamming weights of 4-dimensional linear codes, which are divided into 9 classes in order to get much more information about the relative generalized Hamming weights, and part of the relative generalized Hamming weights of a 4-dimensional linear code with a 1-dimensional subcode are determined.展开更多
C is an [n, k, d]q linear code over Fq. And s(C) = n + 1 - k - d is the Singleton defect of C. An MDS code C with s(C) = 0 has been studied extensively. Recently, a near-MDS code C with s(C) = s(C⊥) = 1 is s...C is an [n, k, d]q linear code over Fq. And s(C) = n + 1 - k - d is the Singleton defect of C. An MDS code C with s(C) = 0 has been studied extensively. Recently, a near-MDS code C with s(C) = s(C⊥) = 1 is studied by many scholars, where C⊥ denotes the dual code of C. This paper concentrates on the linear code C with s(C) = s(C⊥) = 2, and the author calls it an NNMDS code. A series of iff conditions of NNMDS codes are presented. And the author gives an upper bound on length of NNMDS codes. In the last, some examples of NNMDS are given.展开更多
The maximum of g2-d2 for linear [n, k, d; q] codes C is studied. Here d2 is the smallest size of the support of 2-dimensional subcodes of C and g2 is the smallest size of the support of 2-dimensional subcodes of C whi...The maximum of g2-d2 for linear [n, k, d; q] codes C is studied. Here d2 is the smallest size of the support of 2-dimensional subcodes of C and g2 is the smallest size of the support of 2-dimensional subcodes of C which contains a codeword of weight d. The extra cost to the greedy adversary to get two symbols of information using some algorithm is g2-d2. For codes satisfying the fullrank condition of general dimensions, upper bounds on the maximum of g2-d2 are given. Under some condition we have got code C where g2-d2 reaches the upper bound.展开更多
For a binary linear code,a new relation between the intersection and(2,2)-separating property is addressed,and a relation between the intersection and the trellis complexity is also given.Using above relations,the aut...For a binary linear code,a new relation between the intersection and(2,2)-separating property is addressed,and a relation between the intersection and the trellis complexity is also given.Using above relations,the authors will apply several classes of binary codes to secret sharing scheme and determine their trellis complexity and separating properties.The authors also present the properties of the intersection of certain kinds of two-weight binary codes.By using the concept of value function,the intersecting properties of general binary codes are described.展开更多
基金National Natural Science Foundation of Chi-na for Distinguished Young Scholars (No.60225007)National Research Fund for theDoctoral Program of Higher Education ofChina (No.20020248024)Grant-in-Aid forScientific Research(C) (No.14540100)
文摘Identity-based proxy signature enables an entity to delegate its signing rights to another entity in identity-based cryptosystem settings. However, few existing scheme has been proved secure in a formalized model, or acquired optimized performance. To achieve the goals of both proven security and high efficiency, this paper proposed an efficient identity-based proxy signature scheme. The scheme is constructed from bilinear pairing and proved secure in the random oracle model, using the oracle replay attack technique introduced by Pointehval and Stern. The analysis shows that the scheme needs less computation costs and has a shorter signature than the other schemes.
基金Funded partly by Heilongjiang Province Financial Fund for Researchers Returning from Abroad
文摘We developed a novel absolute multi-pole encoder structure to improve the resolution of the multi-pole encoder, realize absolute output and reduce the manufacturing cost of the encoder. The structure includes two ring alnicos defined as index track and sub-division track, respectively. The index track is magnetized based on the improved gray code, with linear halls placed around the track evenly. The outputs of linear halls show the region the rotor belongs to. The sub-division track is magnetized to N-S-N-S (north-south-north-south), and the number of N-S pole pairs is determined by the index track. Three linear hall sensors with an air-gap of 2 mm are used to translate the magnetic filed to voltage signals. The relative offset in a single N-S is obtained through look-up. The magnetic encoder is calibrated using a higher-resolution incremental optical encoder. The pulse output from the optical encoder and hall signals from the magnetic encoder are sampled at the same time and transmitted to a computer, and the relation between them is calculated, and stored in the FLASH of MCU (micro controller unit) for look-up. In the working state, the absolute angle is derived by looking-up with hall signals. The structure is simple and the manufacturing cost is very low and suitable for mass production.
基金supported by the National Natural Science Foundation of China under Grants No.61272499,No.10990011
文摘Signcryption, which was introduced by ZHEN~ is a cryptographic primitive that fulfils the functions of both digital signature and encryption and guarantees confidentiality, integrity and non-repudiation in a more effi- cient way. Certificateless signcryption and pro- xy signcryption in identity-based cryptography were proposed for different applications. Most of these schemes are constructed by bilinear pairings from elliptic curves. However, some schemes were recently presented without pai- rings. In this paper, we present a certificateless proxy identity-based signcryption scheme with- out bilinear pairings, which is efficient and secure.
基金supported by the Hi-Tech Research and Development Program of China under Grant No.2009AA01Z236the National Natural Science Foundation of China under Grants No.60902027,No.60832007 and No.60901018+1 种基金the Funds under Grant No.9140A21030209DZ02the Fundamental Research Funds for the Central Universities under Grants No.ZYGX2009J008,No.ZYGX2009J010
文摘In asynchronous Multiple-Input-Multiple-Output Orthogonal Frequency Division Multiplexing(MIMO-OFDM) over the selective Rayleigh fading channel,the performance of the existing linear detection algorithms improves slowly as the Signal Noise Ratio (SNR) increases.To improve the performance of asynchronous MIMO-OFDM,a low complexity iterative detection algorithm based on linear precoding is proposed in this paper.At the transmitter,the transmitted signals are spread by precoding matrix to achieve the space-frequency diversity gain,and low complexity iterative Interference Cancellation(IC) algorithm is used at the receiver,which relieves the error propagation by the precoding matrix.The performance improvement is verified by simulations.Under the condition of 4 transmitting antennas and 4 receiving antennas at the BER of 10-4,about 6 dB gain is obtained by using our proposed algorithm compared with traditional algorithm.
文摘To solve the problems of the AMR-WB+(Extended Adaptive Multi-Rate-WideBand) semi-open-loop coding mode selection algorithm,features for ACELP(Algebraic Code Excited Linear Prediction) and TCX(Transform Coded eXcitation) classification are investigated.11 classifying features in the AMR-WB+ codec are selected and 2 novel classifying features,i.e.,EFM(Energy Flatness Measurement) and stdEFM(standard deviation of EFM),are proposed.Consequently,a novel semi-open-loop mode selection algorithm based on EFM and selected AMR-WB+ features is proposed.The results of classifying test and listening test show that the performance of the novel algorithm is much better than that of the AMR-WB+ semi-open-loop coding mode selection algorithm.
基金Project(61172022) supported by the National Natural Science Foundation of ChinaProject(GDW20151100010) supported by the State Administration of Foreign Experts Affairs of China
文摘Error codes induced by M-ary modulation and modulation selection in network-based control systems are studied.It is the first time the issue of error codes induced by M-ary modulation is addressed in control field.In network-based control systems,error codes induced by noisy channel can significantly decrease the quality of control.To solve this problem,the network-based control system with delay and noisy channel is firstly modeled as an asynchronous dynamic system(ADS).Secondly,conditions of packet with error codes(PEC)loss rate by using M-ary modulation are obtained based on dynamic output feedback scheme.Thirdly,more importantly,the selection principle of M-ary modulation is proposed according to the measured signal-to-noise ratio(SNR)and conditions of PEC loss rate.Finally,system stability is analyzed and controller is designed through Lyapunov function and linear matrix inequality(LMI)scheme,and numerical simulations are made to demonstrate the effectiveness of the proposed scheme.
文摘In this paper, we study λ-constacyclic codes over the ring R = Z4 + uZ4, where u^2 = 0, for λ= 1 + 3u and 3 + u. We introduce two new Gray maps from R to Z4^4 and show that the Gray images of λ-constacyclic codes over R are quasi-cyclic over Z4. Moreover, we present many examples of λ-constacyclic codes over R whose Z4-images have better parameters than the currently best-known linear codes over Z4.
基金supported by the Foundation of National Natural Science of China under Grant No.11271003the National Science Foundation (USA) under Grant No.DMS-0302549+1 种基金Guangdong Provincial Natural Science Foundation(China)under Grant No.S2012010009950High Level Talents Project of Guangdong,and Scientific Research Project of Education Bureau in Guangzhou under Grant No.2012A004
文摘Any linear code can be used to construct a linear secret sharing scheme.In this paper,it is shown how to decide optimal linear codes(i.e.,with the biggest information rate)realizing a given access structure over finite fields.It amounts to solving a system of quadratic equations constructed from the given access structure and the corresponding adversary structure.The system becomes a linear system for binary codes.An algorithm is also given for finding the adversary structure for any given access structure.
基金supported by the National Natural Science Foundation of China under Grant No.61370089the Natural Science Foundation of Anhui Province under Grant No.1208085MA14+2 种基金the Natural Science Fund of Education Department of Anhui province under Grant No.KJ2013Z276the Fundamental Research Fundsof Hefei University under Grant No.10KY01ZDthe Key construction discipline Funds of Hefei University under Grant No.2014XK08
文摘Constacyclic codes are an important class of linear codes in coding theory.Many optimal linear codes are directly derived from constacyclic codes.In this paper,(1 — uv)-constacyclic codes over the local ring F_p + uF_p + vF_p + uvF_p are studied.It is proved that the image of a(1 — uv)-constacyclic code of length n over F_p + uF_p + vF_p + uvF_p under a Gray map is a distance invariant quasi-cyclic code of index p2 and length p^3n over F_p.Several examples of optimal linear codes over F_p from(1 — uv)-constacyclic codes over F_p + uF_p + vF_p + uvF_p are given.
基金supported by the National Key Basic Research Program of China under Grant No.2013CB834203the National Natural Science Foundation of China under Grant Nos.61472417 and 61472120the Research Council of Norway
文摘This paper proposes a general method to construct 1-resilient Boolean functions by modifying the Tu-Deng and Tang-Carlet-Tang functions. Cryptographic properties such as algebraic degree, nonlinearity and algebraic immunity are also considered. A sufficient condition of the modified func- tions with optimal algebraic degree in terms of the Siegenthaler bound is proposed. The authors obtain a lower bound on the nonlinearity of the Tang-Carlet-Tang functions, which is slightly better than the known result. If the authors do not break the "continuity" of the support and zero sets, the functions constructed in this paper have suboptimal algebraic immunity. Finally, four specific classes of 1-resilient Boolean functions constructed from this construction and with the mentioned good cryptographic properties are proposed. Experimental results show that there are many 1-resilient Boolean functions have higher nonlinearities than known l-resilient functions modified by Tu-Deng and Tang- Carlet-Tang functions.
基金supported by the National Natural Science Foundation of China under Grant Nos.11171366 and 61170257the Special Training Program of Beijing Institute of Technology
文摘Finite projective geometry method is effectively used to study the relative generalized Hamming weights of 4-dimensional linear codes, which are divided into 9 classes in order to get much more information about the relative generalized Hamming weights, and part of the relative generalized Hamming weights of a 4-dimensional linear code with a 1-dimensional subcode are determined.
基金supported by Key Disciplines of Shanghai Municipality under Grant No.S30104
文摘C is an [n, k, d]q linear code over Fq. And s(C) = n + 1 - k - d is the Singleton defect of C. An MDS code C with s(C) = 0 has been studied extensively. Recently, a near-MDS code C with s(C) = s(C⊥) = 1 is studied by many scholars, where C⊥ denotes the dual code of C. This paper concentrates on the linear code C with s(C) = s(C⊥) = 2, and the author calls it an NNMDS code. A series of iff conditions of NNMDS codes are presented. And the author gives an upper bound on length of NNMDS codes. In the last, some examples of NNMDS are given.
基金This paper was presented at International Congress of Mathematicians,August 20-28,2002,BeijingThis work was supported by the Norwegian Research Council and the National NaturalScience Foundation of China(GrantNo.10271116).
文摘The maximum of g2-d2 for linear [n, k, d; q] codes C is studied. Here d2 is the smallest size of the support of 2-dimensional subcodes of C and g2 is the smallest size of the support of 2-dimensional subcodes of C which contains a codeword of weight d. The extra cost to the greedy adversary to get two symbols of information using some algorithm is g2-d2. For codes satisfying the fullrank condition of general dimensions, upper bounds on the maximum of g2-d2 are given. Under some condition we have got code C where g2-d2 reaches the upper bound.
基金supported by the National Science Foundation of China under Grant Nos.11171366 and 61170257
文摘For a binary linear code,a new relation between the intersection and(2,2)-separating property is addressed,and a relation between the intersection and the trellis complexity is also given.Using above relations,the authors will apply several classes of binary codes to secret sharing scheme and determine their trellis complexity and separating properties.The authors also present the properties of the intersection of certain kinds of two-weight binary codes.By using the concept of value function,the intersecting properties of general binary codes are described.