Performance Comparison of Signcryption Schemes – A Step towards Designing Lightweight Cryptographic Mechanism Anuj Kumar Singh #1 , B.D.K.Patro *2 # Research Scholar, Dr. A.P.J.AbdulKalam Technical University, Lucknow, India * Professor, R.B.S. Engineering Technical Campus, Agra, India 1 anujbtechcs@gmail.com 2 bdkpatro@rediffmail.com Abstract—With the advancement of technology and use of heterogeneous devices in today’s communication, computing has become ubiquitous involving devices that are low on computing power and therefore securing communication is necessary in this type of environment. The fundamental security attributes which any system must have includes confidentiality, integrity, authentication and non- repudiation. Signcryption is a new way to achieve confidentiality and authentication simultaneously. Before the advent of signcryption the approach was to first encrypt and then to sign the message, but this scheme had more computational cost and communication overhead. Many signcryption schemes have been developed and implemented so far, but differ in security attributes they provide and computational cost they incur. The strength of these schemes depend upon the difficulty of solving any one problem namely IFP (Integer Factorization Problem), (DLP) Discrete Logarithmic Problem, ECDLP (Elliptic Curve Discrete Logarithmic Problem) or Bilinear Diffie Hellman Problem. This paper analyzes and compares the performance of various signcryption schemes in terms of security attributes and computational cost they take. This analysis provides a way to design Lightweight Cryptographic Mechanism suitable for low computing environments. The last section of the paper provides a generic approach for designing lightweight cryptographic mechanism. Keyword-Performance, Signcryption, Lightweight Cryptography I. INTRODUCTION The technique of Signcryption was coined by YuliangZheng [1] in 1997. Signcryption is relatively a new cryptographic system which combines encryption and authentication in only one logical step. Zheng claimed that signcryption incurs 58% less computational cost and 85% less overhead in comparision to the conventional signature-then-encryption approach. Since the inception of signcryption many signcryption schemes have been given by the authors throughout the years offering different security attributes while having certain advantages and limitations. Also these signcryption schemes are based on DLP (Discrete Logarithmic Problem), ECDLP (Elliptic Curve Discrete Logarithmic Problem) or BDHP (Bilinear Diffie Hellman Problem) [25]. The mechanism of signcryption has been explained in the upcoming section of the paper. II. MECHANISM OF SIGNCRYPTION Signcryption mechanism has three phases namely Initialization Phase, Signcryption Phase and Un-signcryption phase [1]. A. Initialization Phase is intended to select global public parameters used by Alice (Sender) and the Bob (Receiver). The key pair for Alice and Bob is also chosen in this phase. The steps carried out are shown in Figure 1. Figure 1: Steps in Initialization Phase Selection of Public Parameters 1. p and q – two large prime numbers, where q is a largeprime factor of 1 p - 2. g – a random integer inthe range 1, 1 p -     with order q modulo p . 3. KH – a one-way keyed hash function 4. H – a one-way hash function 5. ( ) , E D – Encryption, Decryption Selection of Key Pairs 1. a x – a random number in the range 1, 1 q -     . (Private key of Alice) 2. a y – computed as xa a y g mod p = . (Public key of Alice) 3. b x – a random number in the range 1, 1 q -     . (Private key of Bob) 4. b y – computed as xb b y g mod p = . (Public key of Bob) ISSN (Print) : 2319-8613 ISSN (Online) : 0975-4024 Anuj Kumar Singh et al. / International Journal of Engineering and Technology (IJET) DOI: 10.21817/ijet/2017/v9i2/170902173 Vol 9 No 2 Apr-May 2017 1163