Energy efficient elliptic curve point multiplication for WSN applications

Wireless sensor networks facilitate real-time data processing in many applications such as intrusion detection and military surveillance. These applications inherently demand a high level of security. Public key cryptographic techniques such as Elliptic Curve Cryptography (ECC) provide a flexible interface to ensure security, requiring no pre-distribution of keys. However, ECC is very compute-intensive, owing to the computationally complex elliptic curve point multiplication operation. This work presents a technique to speed up the elliptic curve point multiplication operation, achieving a cost reduction of about 48% over the double and add algorithm and about 40% over the width-w Non Adjacent Form (NAF) algorithm. Additionally, results of its software implementation are also presented, simulating the specifications of MEMSIC's wireless sensor network development kit. Finally, we conclude that the timing results obtained from the software implementation conform to the theoretical results.

Hardware acceleration of cryptographic algorithms is beneficial because considerable performance improvements can be attained compared to software implementations. Thus, hardware implementations can be used in critical applications requiring high encryption or decryption speeds. Parallel architecture with efficient hardware implementation of Galois field arithmetic operations is used to produce high speed computation time for the scalar multiplication operation which is the main operation in Elliptic Curve Cryptography (ECC) system. This work proposed a modification in karatsuba-ofman algorithm which is one of the best algorithms used to perform multiplication operation over Galois field. The modification contrasted on truncating karatsuba-ofman algorithm in a low level and using the classic polynomial multiplication algorithm. In addition, this work proposed architecture for implementing ECC on hardware using Montgomery algorithm in projective coordinates. The results show that the proposed architecture is able to compute GF(2^191) elliptic curve scalar multiplication operations in 72.939 μs on Xilinx Virtex-II XC2V6000 FPGA device and 100.68 μs on Xilinx VirtexE 2600. Also, the proposed architecture can be changed to be suitable for any arbitrary Galois field size with little modifications.KeywordsGalois fieldElliptic curve cryptographyKaratsuba-Ofman multiplierfield programmable gate arrayspolynomial multiplicationpolynomial inversion

Wireless sensor networks (WSNs) facilitate real time monitoring in many commercial and military surveillance applications. These applications automatically call for a high level of security in such networks. Public key cryptographic (PKC) techniques such as Elliptic Curve Cryptography (ECC) provide a flexible interface to ensure security, requiring no pre-distribution of keys. However, ECC is very compute-intensive, owing to the computationally complex elliptic curve point multiplication operation. This work presents a technique to speed up the elliptic curve point multiplication operation, achieving a cost reduction of about 48% over the double and add algorithm and about 40% over the width-w Non Adjacent Form (NAF) algorithm. Additionally, results of its software implementation are presented.

In this work, a new graph has been defined as a main point to design a new version of an asymmetric encryption scheme. This graph is formed based on the scalar multiplication operation on elliptic curve defined over a prime field, which is called an elliptic scalar multiplication (ESM) graph. Some mathematical facts to show the ESM graph is a complete graph are proved theoretically. On the complete elliptic scalar multiplication (CESM) graph, an asymmetric encryption algorithm has been implemented. Fast computations on the proposed algorithm are Z obtained through the matrices representation and determination of the minimum spanning tree (MST) to compute the ciphertext. More secure computations with the CESM graphic encryption algorithm in comparison with the previous asymmetric encryption algorithms. So, the CESM graphic asymmetric encryption algorithm is considered as a new sight for elliptic curve cryptographic usages.

This paper discusses parallelization of elliptic curve cryptography hardware accelerators using elliptic curves over binary fields F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2m</sub> . Elliptic curve point multiplication, which is the operation used in every elliptic curve cryptosystem, is hierarchical in nature, and parallelism can be utilized in different hierarchy levels as shown in many publications. However, a comprehensive analysis on the effects of parallelization has not been previously presented. This paper provides tools for evaluating the use of parallelism and shows where it should be used in order to maximize efficiency. Special attention is given for a family of curves called Koblitz curves because they offer very efficient point multiplication. A new method where the latency of point multiplication is reduced with parallel field arithmetic processors is introduced. It is shown to outperform the previously presented multiple field multiplier techniques in the cases of Koblitz curves and generic curves with fixed base points. A highly efficient general elliptic curve cryptography processor architecture is presented and analyzed. Based on this architecture and analysis on the effects of parallelization, a few designs are implemented on an Altera Stratix II field-programmable gate array (FPGA).

Elliptic curve cryptosystem (ECC) was proposed by Miller [10] and Koblitz [9] which relies on the difficulty of elliptic curve discrete logarithmic problem (ECDLP). It is gaining wide acceptance as an alternative to the conventional public key cryptosystem such as RSA [24], DSA [25], DH [26]. Also it is noted that the wireless sensor networks (WSN) based on the rapid progress of wireless communications and embedded micro electro mechanical systems technologies are becoming important part in our daily life. The security of the WSN becomes one of the major concerns in its applications. Even ECC prominently offers great potential benefits for WSN security there is still a lot of work needs to be done due to WSN has very restraint running conditions such as limited energy source, capability of computing, etc. It is well known that scalar multiplication operation in ECC accounts for about 80% of key calculation time on wireless sensor network motes. In this paper we present an optimized dynamic window based on our previous research works. The whole quality of service (QoS) has been improved under this algorism in particularly the power consuming is more efficiently. The simulation results showed that the average calculation time, due to fuzzy conditions decreased from previous 26 to current 9 as a whole the calculation time, decreased by approximately 18% in comparison to our previous algorithms in an ECC wireless sensor network [23].

An elliptic curve point multiplier (ECPM) is the main part of all elliptic curve cryptography (ECC) systems and its performance is decisive for the performance of the overall cryptosystem. A VLSI residue number system (RNS) architecture of an ECPM is presented in this paper. In the proposed approach, the necessary mathematical conditions that need to be satisfied, in order to replace typical finite field circuits with RNS ones, are investigated. It is shown that such an application is feasible and that it leads to a significant improvement in the execution time of a scalar point multiplication.

We implemented elliptic curve cryptography in the frequency domain on the MSP430 constrained microcontroller. Our implementation of 169-bit elliptic curve cryptography (ECC) on MSP430, one of the most popular microcontrollers for wireless sensor network (WSN) nodes, performs an ECC scalar point multiplication operation, for random points, in only 1.55 ms which is similar to or faster than existing implementations. To our knowledge, this work proposes the first ever software implementation of ECC in the frequency domain on a constrained low-power microcontroller.

We present a high-speed public-key cryptoprocessor that exploits three-level parallelism in Elliptic Curve Cryptography (ECC) over GF(2 n ). The proposed cryptoprocessor employs a Parallelized Modular Arithmetic Logic Unit (P-MALU) that exploits two types of different parallelism for accelerating modular operations. The sequence of scalar multiplications is also accelerated by exploiting Instruction-Level Parallelism (ILP) and processing multiple P-MALU instructions in parallel. The system is programmable and hence independent of the type of the elliptic curves and scalar multiplication algorithms. The synthesis results show that scalar multiplication of ECC over GF(2163) on a generic curve can be computed in 20 and 16 μs respectively for the binary NAF (Non-Adjacent Form) and the Montgomery method. The performance can be accelerated furthermore on a Koblitz curve and reach scalar multiplication of 12 μs with the TNAF (τ-adic NAF) method. This fast performance allows us to perform over 80,000 scalar multiplications per second and to enhance security in wireless mobile applications.

This work presents an evaluation of different software implementations of algorithms to compute the most demanding operation in cryptographic schemes based on Elliptic Curve Cryptography (ECC), the scalar multiplication. Five different methods were studied, including traditional and more sophisticated methods for elliptic curve cryptography defined over prime and binary fields. For evaluation, the key generation algorithm in ECC consisting on a single scalar multiplication was implemented on a P500h LG smarthphone, which includes an ARM processor running at 600MHz. Both execution time and memory usage was evaluated. It was found that in general, scalar multiplication runs 8 times faster for ECC defined over prime fields, being the NAF the best performer method. For ECC over binary fields, the best performer method was wNAF. The results presented in this work could help a designer to select the most appropriate method when implementing ECC-based cryptographic schemes such as encryption or digital signatures on mobile devices like smartphones, meeting implementation requirements in terms of execution time and memory usage.

Pseudo-random scalar multiplication based on group isomorphism

Elliptic curves cryptography was introduced independently by Victor Miller (Miller, 1986) and Neal Koblitz (Koblitz, 1987(Koblitz, ) in 1985. .At that time elliptic curve cryptography was not actually seen as a promising cryptographic technique.As time progress and further research and intensive development done especially on the implementation side, elliptic curve cryptography is now being implemented widely.Elliptic curves cryptography offers smaller key size, bandwidth savings and faster in implementations when compared to the RSA (Rivest-Shamir-Adleman) cryptography which based its security on the integer factorization problem.The most interesting feature of the elliptic curves is the group structure of the points generated by the curves, where points on the elliptic curves form a group.The security of elliptic curves cryptography relies on the elliptic curves discrete logarithm problem.The elliptic curve discrete logarithm problem is analogous to the ordinary algebraic discrete logarithm problem, l = g x , where given the l and g, it is infeasible to compute the x.Elliptic curve discrete logarithm problem deals with solving for n the relation P = nG.Given the point P and the point G, then it is very hard to find the integer n.To implement the discrete logarithm problem in elliptic curve cryptography, the main task is to compute the order of group of the curves or in other words the number of points on the curve.Computation to find the number of points on a curve, has given rise to several point counting algorithms.The Schoof and the SEA (Schoof-Elkies-Atkin) point counting algorithms will be part of the discussion in this chapter.This chapter is organized as follows: Section 2, gives some preliminaries on elliptic curves, and in section 3, elliptic curve discrete logarithm problem is discussed.Some relevant issues on elliptic curve cryptography is discussed in section 4, in which the Diffie-Hellman key exchange scheme, ElGamal elliptic curve cryptosystem and elliptic curve digital signature scheme are discussed here accompanied with some examples.Section 5 discussed the two point counting algorithms, Schoof algorithm and the SEA (Schoof-Elkies-Atkin) algorithm.Following the discussion in section 5, section 6 summaries some similarities and the differences between these two algorithms.Section 7 gives some brief literature on these two point counting algorithms.Finally, section 8 is the concluding remarks for this chapter. Elliptic curvesElliptic curves obtained their name from their relation to elliptic integrals that arise from the computation of the arc length of ellipses (Lawrence & Wade, 2006).Elliptic curves are www.intechopen.com Cryptography and Security in Computing1 1 2 3 4 2 2 4 Fig. 1.1. 2(1 ) (1 ) yx x x   www.intechopen.com

This research addresses the computationallyeffective implementation of cryptographic protocols based on elliptic curves, and targets in particular cryptosystems that should be hosted on embedded programmable processors. In principle, the implementation of Elliptic Curve Cryptography&#13;\n(ECC) requires one to deal with different design options, which stem from the available degrees of freedom: elliptic curve family, coordinate system, and point multiplication procedure. On the other hand, theoretical studies already proved that exist only a few setups leading to computational efficient implementations. The goal of present paper is to analyze from an applicative point of view such setups, which mainly involve two specific&#13;\nfamilies of elliptic curves: Edwards curves and extend Jacobi quartic curves. The presented experimental session shows a few interesting outcomes; first, ECC schemes implemented by using either Edwards curves or extended Jacobi quartic curves can obtain remarkable performances in terms of computational efficiency also on low-cost, low-resources processors. Second, the experiments showed that in some cases the number of Fp operations is not enough to accurately estimate the overall performance of an ECC-based cryptosystem.

With the rapid development of cloud computing, e-commerce, authentication among multi-robot systems, the highspeed implementation of Elliptic Curve Cryptography (ECC) is in widespread use. The performance of ECC is decided by the design of scalar point multiplier, which is one of the most time-consuming component. This paper presents a full set of methods to achieve an ultra high-speed scalar point multiplier, its Scalar Point Multiplication (SPM) is optimized comprehensively in terms of speed-first design approach by concurrently implementing the Point-add (PA) and Point-double (PD) algorithms, improving large integer modular inversion algorithm and large integer modular multiplication algorithm. Finally, Montgomery domain operation and Non-Adjacent Form (NAF) encoding theory are applied to enhance the speed of scalar point multiplier. In the VLSI design, a high-speed $\pmb{256\times 256}$ -bit scalar point multiplier is achieved based on SMIC's 65nm process. It can complete single calculation of SPM within 12.5us on average, in other word, 80,000 times of SPM can be computed in one second. Compared to the scalar point multiplier realized by other publications based on VLSI, the reports for circuits synthesis show that our multiplier is optimal in terms of $AT^{2}$ and ultrafast in terms of speed.

Mobile and wireless devices like cell phones and network enhanced PDAs have become increasingly popular in recent years. The security of data transmitted via these devices has become the bottleneck for wireless network. Elliptic curves cryptography (ECC) is especially attractive for devices and is suited for wireless network, which has restrictions of the limited bandwidth, processing power, storage space and power consumption. The efficiency of ECC implementation is highly dependent on the performance of arithmetic operations of scalar multiplication(SM) dP, which mainly applied in encryption, signature and protocol. A new signed binary representation (SBR) for integers is proposed, which needs less memory and cost of computation compared to other methods mentioned in this paper. According to analyzing and comparing to other methods, algorithm for computing dP using new SBR is more efficient in window methods and is the simplest for applying in software and hardware. The new SBR needs less computational power and memory and can improve the security of wireless network efficiently.