利用Matlab软件提供的图形用户界面(Graphical User Interfaces GUI)设计甲骨文字体.首先介绍了一些概念及B样条圆域曲线的绘制然后利用该算法设计字体.因为甲骨文在书写时线条粗细不一从而引进了圆域曲线,并且介绍了它的基本性质及算法...利用Matlab软件提供的图形用户界面(Graphical User Interfaces GUI)设计甲骨文字体.首先介绍了一些概念及B样条圆域曲线的绘制然后利用该算法设计字体.因为甲骨文在书写时线条粗细不一从而引进了圆域曲线,并且介绍了它的基本性质及算法.然后利用圆域B样条曲线来设计甲骨文字体.最后在圆域B样条曲线的基础上,对圆头体进行改进,将等半径的圆域改成椭圆域,然后设计甲骨文.这样书写出的甲骨文线条的边缘看上去更自然些。展开更多
The idea behind a (t, n) threshold blind signature is that a user can ask at least t out of n players of a group to cooperate to generate a signature for a message without revealing its content. This paper first prese...The idea behind a (t, n) threshold blind signature is that a user can ask at least t out of n players of a group to cooperate to generate a signature for a message without revealing its content. This paper first presents a new blind signature scheme from Weil pairing on elliptic curves. Based on this scheme, a threshold blind signature scheme is proposed. It is efficient and has the security properties of robustness and unforgeability. In the proposed scheme, the group manger is introduced to take the role of distributing the group secret key to each player. However, he cannot forge the players to generate partial blind signatures (Each partial blind signature depends on not only the secret key of the player, but also a random number the player picks). Compared with a threshold signature with a trusted third party, its advantage is obvious; Compared with a threshold signature without a trusted third party, it is more simple and efficient.展开更多
The security of wireless local area network （WI.AN） becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to t...The security of wireless local area network （WI.AN） becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to the serious secure leak in IEEES02.11 standards, it is impossible to utterly solve the problem by simply adding some remedies. Based on the analysis on the security mechanism of WLAN and the latest techniques of WI.AN security, a solution to WLAN security was presented. The solution makes preparation for the further combination of WLAN and Internet.展开更多
The design and implementation of fast algorithms related to Elliptic Curve Cryptography (ECC) over the field GF(p), such as modular addition, modular subtraction, point addition, point production, choice of embedding ...The design and implementation of fast algorithms related to Elliptic Curve Cryptography (ECC) over the field GF(p), such as modular addition, modular subtraction, point addition, point production, choice of embedding plaintext to a point, etc. are given. A practical software library has been produced which supports variable length implementation of the ECCbased ElGamal cryptosystem. More importantly, this scalable architecture of the design enables the ECC being used in restricted platforms as well as high-end servers based on Intel Pentium CPU. Applications such as electronic commerce security, data encryption communication, etc.are thus made possible for real time and effective ECC.展开更多
In this paper, we present two explicit invalid-curve attacks on the genus 2 hyperelliptic curve over a finite field. First, we propose two explicit attack models by injecting a one-bit fault in a given divisor. Then, ...In this paper, we present two explicit invalid-curve attacks on the genus 2 hyperelliptic curve over a finite field. First, we propose two explicit attack models by injecting a one-bit fault in a given divisor. Then, we discuss the construction of an invalid curve based on the faulted divisor. Our attacks are based on the fact that the Hyperelliptic Curve Scalar Multiplication (HECSM) algorithm does not utilize the curve parameters and We consider three hyperelliptic curves as the attack targets. For curve with security level 186 (in bits), our attack method can get the weakest invalid curve with security level 42 (in bits); there are 93 invalid curves with security level less than 50. We also estimate the theoretical probability of getting a weak hyperelliptic curve whose cardinality is a smooth integer. Finally, we show that the complexity of the fault attack is subexponential if the attacker can freely inject a fault in the input divisor. Cryptosystems based on the genus 2 hyperelliptic curves cannot work against our attack algorithm in practice.展开更多
In this paper,the integer N = pkq is called a <k,1>-integer,if p and q are odd primes with almost the same size and k is a positive integer. Such integers were previously proposed for various cryptographic appli...In this paper,the integer N = pkq is called a <k,1>-integer,if p and q are odd primes with almost the same size and k is a positive integer. Such integers were previously proposed for various cryptographic applications. The conditional factorization based on lattice theory for n-bit <k,1>-integersis considered,and there is an algorithm in time polynomial in n to factor these integers if the least significant 「((2k-1)n)/((3k-1)(k+1))」bits of p are given.展开更多
文摘利用Matlab软件提供的图形用户界面(Graphical User Interfaces GUI)设计甲骨文字体.首先介绍了一些概念及B样条圆域曲线的绘制然后利用该算法设计字体.因为甲骨文在书写时线条粗细不一从而引进了圆域曲线,并且介绍了它的基本性质及算法.然后利用圆域B样条曲线来设计甲骨文字体.最后在圆域B样条曲线的基础上,对圆头体进行改进,将等半径的圆域改成椭圆域,然后设计甲骨文.这样书写出的甲骨文线条的边缘看上去更自然些。
基金Supported by the National 973 Project of China(No.G1999035803)the National Natural Science Foundation of China (No.60373104)the National 863 Project of China (No.2002AA143021)
文摘The idea behind a (t, n) threshold blind signature is that a user can ask at least t out of n players of a group to cooperate to generate a signature for a message without revealing its content. This paper first presents a new blind signature scheme from Weil pairing on elliptic curves. Based on this scheme, a threshold blind signature scheme is proposed. It is efficient and has the security properties of robustness and unforgeability. In the proposed scheme, the group manger is introduced to take the role of distributing the group secret key to each player. However, he cannot forge the players to generate partial blind signatures (Each partial blind signature depends on not only the secret key of the player, but also a random number the player picks). Compared with a threshold signature with a trusted third party, its advantage is obvious; Compared with a threshold signature without a trusted third party, it is more simple and efficient.
基金The National Natural Science Foundation ofChina(No60703031)The Natural Science Foundation of Shaanxi Province ( No2007F50)
文摘The security of wireless local area network （WI.AN） becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to the serious secure leak in IEEES02.11 standards, it is impossible to utterly solve the problem by simply adding some remedies. Based on the analysis on the security mechanism of WLAN and the latest techniques of WI.AN security, a solution to WLAN security was presented. The solution makes preparation for the further combination of WLAN and Internet.
基金the National Natural Science Foundation of China(No.60271025)
文摘The design and implementation of fast algorithms related to Elliptic Curve Cryptography (ECC) over the field GF(p), such as modular addition, modular subtraction, point addition, point production, choice of embedding plaintext to a point, etc. are given. A practical software library has been produced which supports variable length implementation of the ECCbased ElGamal cryptosystem. More importantly, this scalable architecture of the design enables the ECC being used in restricted platforms as well as high-end servers based on Intel Pentium CPU. Applications such as electronic commerce security, data encryption communication, etc.are thus made possible for real time and effective ECC.
基金supported by the National Basic Research Program （973 Program）under Grant No.2013CB834205 the National Natural Science Foundation of China under Grant No.61272035 the Independent Innovation Foundation of Shandong University under Grant No.2012JC020
文摘In this paper, we present two explicit invalid-curve attacks on the genus 2 hyperelliptic curve over a finite field. First, we propose two explicit attack models by injecting a one-bit fault in a given divisor. Then, we discuss the construction of an invalid curve based on the faulted divisor. Our attacks are based on the fact that the Hyperelliptic Curve Scalar Multiplication (HECSM) algorithm does not utilize the curve parameters and We consider three hyperelliptic curves as the attack targets. For curve with security level 186 (in bits), our attack method can get the weakest invalid curve with security level 42 (in bits); there are 93 invalid curves with security level less than 50. We also estimate the theoretical probability of getting a weak hyperelliptic curve whose cardinality is a smooth integer. Finally, we show that the complexity of the fault attack is subexponential if the attacker can freely inject a fault in the input divisor. Cryptosystems based on the genus 2 hyperelliptic curves cannot work against our attack algorithm in practice.
基金Supported by NNSF of China and SF of Chinese Education Committee ,and has been done when the author visited the Department of Mathematics of Purduc Unuversity in 1993
文摘It is a survey of the problem on class numbers of quadratic number fields.
基金the National Natural Science Foundation of China (No.60473021).
文摘In this paper,the integer N = pkq is called a <k,1>-integer,if p and q are odd primes with almost the same size and k is a positive integer. Such integers were previously proposed for various cryptographic applications. The conditional factorization based on lattice theory for n-bit <k,1>-integersis considered,and there is an algorithm in time polynomial in n to factor these integers if the least significant 「((2k-1)n)/((3k-1)(k+1))」bits of p are given.
基金supported by National Natural Science Foundation of China (Grant No.10990011)the Science Research Startup Foundation of North China University of Technology
文摘In this paper,the number of isomorphism classes of Legendre elliptic curves over finite field is enumerated.
