Several classes of even-variable 1-resilient rotation symmetric Boolean functions with high algebraic degree and nonlinearity

Recent research shows that the class of rotation symmetric Boolean functions is potentially rich in functions of cryptographic significance. In this paper, some classes of 2m-variable (m is an odd integer) 1-resilient rotation symmetric Boolean functions are got, whose nonlinearity and algebraic degree are studied. For the first time, we obtain 2m-variable 1-resilient rotation symmetric Boolean functions having high nonlinearity and optimal algebraic degree. In addition, we obtain a class of non-linear rotation symmetric 1-resilient function for every $n\ge 5$, and a class of quadratic rotation symmetric $(k?1)$-resilient function of $n=3k$ variables, where k is an integer.     

Fast algorithms for computing isogenies between ordinary elliptic curves in small characteristic

The problem of computing an explicit isogeny between two given elliptic curves over Fq, originally motivated by point counting, has recently awaken new interest in the cryptology community thanks to the works of Teske and Rostovtsev & Stolbunov.While the large characteristic case is well understood, only suboptimal algorithms are known in small characteristic; they are due to Couveignes, Lercier, Lercier & Joux and Lercier & Sirvent. In this paper we discuss the differences between them and run some comparative experiments. We also present the first complete implementation of Couveignes' second algorithm and present improvements that make it the algorithm having the best asymptotic complexity in the degree of the isogeny.     

An all optical approach for developing a system involving Kerr material based switches for cryptographic encoding of binary data depending on the input parity

Optics is a highly potential candidate in super fast data computation and communication because of its strong inherent parallelism. Several all optical logic, arithmetic and data processing systems have been proposed in the last few decades. Many all optical digital encoders and decoders are also reported. In this paper we propose a new and alternative concept of using optics for encrypting a binary number to a suitable binary code to achieve a secured optical communication. This binary number can bear the supporting alphabets and numerals in communication of data. In this process an encrypted data is checked by necessary parity bit to ensure a secure communication. The result is verified using proper simulation.     

Bounds and Combinatorial Structure of (k,n) Multi-Receiver A-Codes

In the model of(k,n) multi-receiver authentication codes ( A-codes),a transmitter broadcasts a message m to nreceivers in such a way that not only an outside opponent butalso any k-1 receivers cannot cheat any other receiver.In this paper, we derive lower bounds on the cheating probabilitiesand the sizes of keys of (k,n) multi-receiver A-codes.The scheme proposed by Desmedt, Frankel and Yung meets all ourbounds with equalities. This means that our bounds are tightand their scheme is optimum. We further show a combinatorialstructure of optimum (k,n) multi-receiver A-codes.A notion of TWOOAs is introduced. A TWOOA is a pair of orthogonalarrays which satisfy a certain condition. We then prove thatan optimum (k,n) multi-receiver A-codeis equivalent to a TWOOA.     

量子密码术

根据量子力学中的海森伯不确定性原理 ,任何窃听者无法窃听量子密码通信中的信息而不被发现 ,本文讲述了量子密钥生成的基本原理 ,介绍了当前实验研究的进展 ,面临的技术挑战及安全性问题 ,最后展望了发展前景和今后的发展方向。     

Maximal values of generalized algebraic immunity

The notion of algebraic immunity of Boolean functions has been generalized in several ways to vector-valued functions and/or over arbitrary finite fields and reasonable upper bounds for such generalized algebraic immunities has been proved in Armknecht and Krause (Proceedings of ICALP 2006, LNCS, vol. 4052, pp 180–191, 2006), Ars and Faugere (Algebraic immunity of functions over finite fields, INRIA, No report 5532, 2005) and Batten (Canteaut, Viswanathan (eds.) Progress in Cryptology—INDOCRYPT 2004, LNCS, vol. 3348, pp 84–91, 2004). In this paper we show that the upper bounds can be reached as the maximal values of algebraic immunities for most of generalizations by using properties of Reed–Muller codes.      

Sequential and dynamic frameproof codes

There are many schemes in the literature for protecting digital data from piracy by the use of digital fingerprinting, such as frameproof codes and traitor-tracing schemes. The concept of traitor-tracing has been applied to a digital broadcast setting in the form of dynamic traitor-tracing schemes and sequential traitor-tracing schemes, which could be used to combat piracy of pay-TV broadcasts, for example. In this paper, we extend the properties of frameproof codes to this dynamic model, defining and constructing both l-sequential c-frameproof codes and l-dynamic c-frameproof codes. We also give bounds on the number of users supported by such schemes.      

Efficiency and security problems of anonymous key agreement protocol based on chaotic maps

In 2011, Niu-Wang proposed an anonymous key agreement protocol based on chaotic maps in [Niu Y, Wang X. An anonymous key agreement protocol based on chaotic maps. Commun Nonlinear Sci Simulat 2011;16(4):1986-92]. Niu-Wang’s protocol not only achieves session key agreement between a server and a user, but also allows the user to anonymously interact with the server. Nevertheless, this paper points out that Niu-Wang’s protocol has the following efficiency and security problems: (1) The protocol has computational efficiency problem when a trusted third party decrypts the user sending message. (2) The protocol is vulnerable to Denial of Service (DoS) attack based on illegal message modification by an attacker.     

A quasi quadratic time algorithm for hyperelliptic curve point counting

We describe an algorithm to compute the cardinality of Jacobians of ordinary hyperelliptic curves of small genus over finite fields with cost . This algorithm is derived from ideas due to Mestre. More precisely, we state the mathematical background behind Mestre’s algorithm and develop from it a variant with quasi-quadratic time complexity. Among others, we present an algorithm to find roots of a system of generalized Artin-Schreier equations and give results that we obtain with an efficient implementation. Especially, we were able to obtain the cardinality of curves of genus one, two or three in finite fields of huge size. 2000 Mathematics Subject Classification Primary—11S40, 14H42, 11G20, 11G15, 94A60