International Journal of Computer Applications (0975 – 8887) Volume 72– No.13, May 2013 33 138Performance Analysis of BEST and NJJSAA Prachi Saxena Department Of CSE, NRI, College, Bhopal, INDIA Sini Shibu Department Of CSE, NRI College, Bhopal, INDIA ABSTRACT With the rapid growing of internet, information security becomes significant to protect secret and personal data. Encryption algorithm plays an important role for data security. In this paper, authors have evaluated the performance of two symmetric key encryption algorithms: BEST and NJJSAA used for data encryption and Analysed the encryption security, evaluated encryption speed for both algorithms. Experimental results show that BEST algorithm runs faster than NJJSAA algorithm while NJJSAA provide more security than BEST on the basis of Avalanche Effect. Keywords Computer Security, Encryption, Decryption, Algorithm, Symmetric Key, BEST, NJJSA 1. INTRODUCTION Smaller devices like PDA, smart cards etc. require fast and efficient ciphers for encryption. To encrypt information securely, 128 bit key needs more computing and cost than 64 bits. It is always not true that “Larger Key size provides more security”. In this age of Information Technology, every information is communicated through internet and the security to these information systems is inevitable. Different systems need security for different time period. Take examples of the following scenarios [9]:  Funds are transferred electronically all over the world through net. Security is required for brief period for this transaction.  Companies make strategic plans, which should be confidential for lesser number of years.  Some formulas and designs of proprietary products need to be protected for their lifetime.  Confidential information of an individual (employment evaluation, monetary data) may need security for its lifetime. For such scenarios, the security is important and this type of information has to be encrypted in a faster and efficient way. In [10] it is discussed that why information security is of so much importance. It may be expensive to protect information but we can do it by using some economic models to secure the information [11]. Lucifer[12] was a cryptographic algorithm developed by Horst Feistel at IBM. The feistel structure was first seen in this cipher. Lucifer had 128- bit block size and 128 bit key. It was submitted to NIST as a candidature for DES. NIST acknowledged Lucifer and reduced it to 56-bit key and 64- bit block cipher[13] and made it as Data Encryption Standard. When NIST reduced its Key and block size, it was looked down by the cryptographers around the world as malicious attempt for backdoor entry and to eavesdrop DES[15]. This was never proved [14]. DES ruled the world from 1977 till it was superseded by AES in 2002.Biham and Shamir[16] tried differential cryptanalysis on DES like crypto systems. D. Copersmith[17] showed some of the safeguards against differential cryptanalysis. Denning predicted [18] that DES would no longer be a standard after 15 years as more attempts will be made to break DES. The first successful computer experiment on 16-round DES was published in [19]. Even with reduced key size and after public scrutiny for more than 20 years, DES was able to withstand all attacks. This motivated the author to develop a new cryptographic encryption/ decryption algorithm which improve the throughput, encryption time and other parameters of existing algorithm. For this author have studied many existing algorithms and presented its conclusion on it. There are three type of cryptography algorithm: public key, symmetric key algorithms, and hash functions. While the first two algorithms are used for encryption and decryption of the data, and the hash functions are one-way functions that don’t allow the reverse processed. As we know that encryption algorithms are used in computer communications or exchanging information in network to provide secure transfers. Whenever an algorithm is used in a transfer, the file is first translated into a meaningless cipher text and then transferred; at the receiving end, computer uses a key value to translate the cipher into its original form. So if the data or file is intercepted before it reaches the receiving end computer it is in an unusable (or encrypted) form [4]. Cryptography process can be control through key where it is a piece of information and permits an encrypted string to be decoded. In fact, the key we chose will provide the only means to decrypt data that was encrypted with that key, so not only must we choose the key carefully, we must never change it if we intend use it for persistent data. It goes without saying that we should guard our key carefully. If someone gains access to our key, the data will be easily decoded [1]. If our server is not totally under our control it's impossible to ensure key security so we may want to think carefully before using it for anything that requires high security, like storing credit card numbers. The key should be as random a string as we can concoct, with numbers and uppercase and lowercase letters. Our key should not be a simple text string. In order to be cryptographically secure it needs to be as random as possible [18]. At one side, high security is the basic requirement of data encryption algorithm and on the other side, encryption algorithms are known to be computationally intensive. They consume a significant amount of computing resources such as CPU time, memory, and battery power. Especially for a wireless device, usually with very limited resources (e.g. battery) is subject to the problem of energy consumption due