Short Paper: Enhancing Wi-Fi Security Using a Hybrid Algorithm of Blowfish and RC6 Nusrat Jahan Oishi, Md.Arafin Mahamud,Asaduzzaman Computer Science & Engineering Chittagong University of Engineering & Technology Chittagong, Bangladesh cse_oishi@yahoo.com, arefin.cuet@gmail.com, asadcuet@gmail.com Abstract— Nowadays, Wi-Fi is a very popular Technology. Faster data transfer and Security both are very important for Wi-Fi. At present, Advanced Encryption Standard (AES) is used for Wi-Fi that is more secured than other encryption algorithms but it is not so fast because of it’s complex functions. On the other hand, Blowfish is a very faster encryption algorithm but it cannot apply on Wi-Fi because of it’s security problems. In this paper, a hybrid algorithm of Blowfish and Rivest Cipher 6 (RC6) is proposed that solves the security problems of Blowfish and also maintains the fastness of Blowfish and makes it able to use it in place of AES. It uses two innovative criteria. One is ingenious confusion process using two random numbers “a” and “w” that removes reflectively weak key attack and Known plaintext attack of Blowfish. The other is usage of one S-Box by overlapping process that eliminates the collision key attack of Blowfish. Sub key generation process of this algorithm also removes the Brute Force attack of AES. This paper tries to give an efficient algorithm that enhances the performance of Blowfish algorithm by adding a function of RC6 with it. The adding process is trickily handed here that makes the proposed algorithm as fast as Blowfish and also secured like existing AES. The proposed algorithm takes less encryption –decryption time like Blowfish and also secured like AES. Throughput, Average time for different data lengths and attack removal process are used to measure the efficiency of this proposed algorithm. Keywords—Blowfish;RC6;Collision key attack;Known plaintext attack;reflectively weak key attack (key words) I. INTRODUCTION Wi-Fi is a very popular technology but security is a matter of great concern for the field of Wi-Fi. Among many security processes, Cryptography is very popular network security process where the message of any formats is converted into a encrypted version that is unreadable by a human or computer. There are two types of cryptography Algorithms are found: one is Symmetric key cryptography where same key is used for both encryption and decryption(e.g. AES,Blowfish,RC6)and the another is Asymmetric key cryptography where different keys are used for encryption and decryption(e.g. RSA). At present, AES [2] Symmetric key encryption algorithm is used for Wi-Fi network security but it is not so fast. On the other hand Blowfish algorithm is so fast but it has some security problems. In this paper, a 128 bit hybrid algorithm of Blowfish and RC6 is proposed that removes the security problems of Blowfish and also take less Encryption decryption time than AES. A. Blowfish In [1], Blowfish is 64 bit symmetric key algorithm which contains eighteen 32 bit sub keys and four 32bit S-boxes with 256 entries each. The main function of it is given below: The Encryption process of Blowfish is , The input is a 64-bit data element, x. Divide x into two 32-bit halves: xL, xR. Then, for i= 1 to 16. XL = XL XOR Pi XR = F(XL) XOR XR Swap XL and XR After the sixteenth round, swap XL and XR again to undo the last swap. Then, XR = XR XOR P17 and XL = XL XOR P18. Finally, recombine XL and XR to get the cipher text. The F function is: F(XL) = ((S1,A + S2,B mod 2^32) XOR S3,C) + S4,D mod 2^32. Here 64 bit is divided among A,B,C,D registers where each of the register contains 8 bit. B. RC6 In [3], RC6 is a 128 bit symmetric key encryption algorithm. The procedure is given below: • Input: Plaintext is stored in four w-bit input registers A,B,C,D .Number r of rounds. w-bit round keys S[0,…….,2r+3]. • Output: cipher text is stored in A,B,C,D. • Procedure: B=B+S[0] D=D+S[1] For i=1 to r do { t=(B+(2B+1)) <<< lgw u=(D+(2D+1))<<< lgw A=((A XOR t) <<< u)+S[2i] C=((C XOR u) <<< t)+S[2i+1] (A,B,C,D) = (B,C,D,A) } A = A+S[2r+2] C = C+S[2r+3] 978-1-5090-0203-0/16/$31.00 ©2016 IEEE