Design of a New Security Protocol Using Hybrid Cryptography

Subasree & Sakthivel ? propose of a New Security protocol IJRRAS 2 (2) ? February 2010 DESIGN OF A NEW SECURITY PROTOCOL USING crown of thorns CRYPTOGRAPHY ALGORITHMS S. Subasree and N. K. Sakthivel School of Computing, Sastra University, Thanjavur 613401, Tamil Nadu, INDIA. ABSTRACT A countr Network is an interconnected group of autono mous computing nodes, which use a well defined, mutually agree set of rules and conventions known as converses protocols, interact with one -another meaningfully and allow resource sharing preferably in a predictable and controllable manner. confabulation has a majo r impact on today? s business. It is desired to communicate data with high security. Security accesss compromises the security and hence various Symmetric and irregular cryptanalytic algorithms accommodate been proposed to achieve the security services such as Authentication, Confidentiality, Integrity, Non-Repudiation and Availability. At present, various types of cryptographic algorithms provide high security to information on controlled networks. These algorithms atomic number 18 required to provide data security and users authenticity.To improve the strength of these security algorithms, a new security protocol for on line exercise can be designed victimization combination of both symmetric and asymmetric cryptographic techniques. This protocol provides third cryptographic pr imitives such as integrity, confidentiality and authentication. These three primitives can be achieved with the help of oval burn cryptanalysis, triple -RSA algorithm and Message Digest MD5. That is it uses Elliptic Curve cryptograph for encryption, Dual -RSA algorithm for authentication and MD-5 for integrity.This new security protocol has been designed for better security with integrity using a combination of both symmetric and asymmetric cryptographic techniques. strikewords Network Security, Elliptic Curve Cryptography, Dual-RSA, Message Digest-5. 1. INTRODUCTION Curio sity is one of the most common human traits, matched by the wish to cloak private information. Spies and the phalanx all resort to information hiding to pass messages securely, some clock times deliberately including misleading information 12. Steganography, a mechanism for hiding information in obviously innocent pictures, may be employ on its own or with other methods.Encryption fundamentally consists of scrambling a message so that its contents are not readily accessible while decryption is the reversing of that process14. These processes depend on particular algorithms, known as engraves. Suitably scrambled text is known as bet text while the victor is, not surprising ly, redundant text. Readability is neither a necessary nor sufficient condition for something to be plain text. The original might well not make any obvious virtuoso when read, as would be the case, for example, if something already encrypted were being further encrypted.Its alike quite accomplishable t o construct a mechanism whose take is readable text but which actually bears no relationship to the unencrypted original. A key is used in coalition with a cipher to encrypt or decrypt text. The key might appear meaningful, as would be the case with a character string used as a password, but this transformation is irrelevant, the positionality of a key lies in its being a string of bits determining the mapping of the plain text to the cipher text. 1. 1 Why we need cryptanalytics?Protecting access to information for reasons of security is still a major reason for using cryptography. However, its also more and more used for identification of individuals, for authentication and for non -repudiation. This is particularly important with the growth of the Internet, global trading and other activities12. The identity of e -mail and Web users is trivially easy to conceal or to forge, and secure authentication can give those interacting remotely confidence that theyre dealing with the right person and that a message hasnt been forged or changed.In commercialised situations, non-repudiation 12 is an important concept ensuring that if, say, a contract has been agreed upon one party cant then renege by claiming that they didnt actually agree or did so at some different time when, perhaps, a price was higher or lower. Digital signatures and digital timestamps are used in such situations, often in conjunction with other mechanisms such as message digests and digital certificates. 95 Subasree & Sakthivel ? Design of a New Security protocol IJRRAS 2 (2) ? February 2010The range of uses for cryptography and related techniques is considerable and growing steadily. Passwords are common but the protection they offer is often illusory, perhaps because security policies within many organizations arent well concept out and their use causes more problems and inconvenience than seems worth it14,15. In many cases where passwords are used, for example in protecting word process ed documents, the ciphers used are extremely lightweight and can be attacked without difficulty using one of a range of freely available cracking programs. 2.TYPES OF CRYPTOGRAPHIC ALGORITHMS 2. 1. Elliptic Curve Encryption When using elliptic curves in cryptography11, we use various properties of the points on the curve , and functions on them as well. Thus, one common task to complete when using elliptic curves as an encryption tool is to find a way to turn information m into a point P on a curve E. We assume the information m is already written as a number. There are many ways to do this, as frank as setting the letters a = 0, b = 1, c = 2, . . . or there are other methods, such as ASCII, which accomplish the a analogous(p) task.Now, if we have E y2 = x3 + Ax + B (mod p), a curve in Weierstrass form, we want to let m = x. But, this will only work if m3 + Am + B is a unbowed modulo p. Since only half of the numbers modulo p are squares, we only have astir(predicate) a 50% cha nce of this occurring. Thus, we will sift to institute the information m into a take account that is a square. Pick some K such that 1/2K is an acceptable failure rate for embedding the information into a point on the curve. Also, make sure that (m + 1)K p. Let xj = mK + j for j = 0, 1, 2, . . . ,K ? 1 Compute x 3j + Axj + B.Calculate its square root yj (mod p), if possible. If there is a square root, we let our point on E representing m be P m = (xj , yj) If there is no square root, try the next value of j4,5. So, for from each one value of j we have a probability of about 1/2 that xj is a square modulo p. Thus, the probability that no xj is a square is about 1/2K, which was the acceptable failure rate6. In most common applications, there are many real-life problems that may occur to damage an attempt at send a message, like computer or electricity failure.Since people accept a certain 16 amount of failure due to uncontrollable phenomenon, it makes sense that they could agree on an acceptable rate of failure for a controllable feature of the process. Though we will not use this specific process in our algorithms10. 2. 2. Dual RSA In practice, the RSA decryption computations are performed in p and q and then combined via the Chinese Remainder Theorem (cathode-ray tube) to obtain the desired solution in ? N, rather of directly computing the exponentiation in ? N. This decreases the computational costs of decryption In two ways.First, computations in ? p and ? q are more efficient than the same computations in ? N since the elements are much smaller. Second, from Lagrange? s Theorem, we can replace the private exponent d with dp = d mod (p 1) for the computation in ? p and with dq = d mod (q 1) for the computation in ? p, which reduce the cost for each exponentiation when d is larger than the primes. It is common to refer to dp and dq as the CRT -exponents. The first method to use the CRT for decryption was proposed by Quisquater and Couvreur 7,8.Since t he method requires knowledge of p and q, the key contemporaries algorithm needs to be modified to output the private key (d, p, q) instead of (d,N). Given the pri vate key (d, p,q) and a valid ciphertext C ? ? N, the CRTdecryption algorithm is as follows 1) Compute Cp = Cdp mod p. 2) Compute Cq = Cdq mod q. 3) Compute M0 = (Cq Cp) . p-1 mod q. 4) Compute the plaintext M = Cp + M0 . p. This version of CRT-decryption is simply Garner? s Algorithm for the Chinese Remainder Theorem applied to RSA.If the key generation algorithm is further modified to output the private key (dp, dq, p, q, p -1 mod q), the computational cost of CRT-decryption is dominated by the modular exponentiations in go 1) and 2) of the algorithm. When the primes p and q are roughly the same size (i. e. , half the size of the modulus), the computational cost for decryption using CRT -decryption (without parallelism) is theoretically 1/4 the cost for decryption using the original method7. Using RSA-Small-e along wi th CRT-decryption allows for extremely fast encryption and decryption that is at most quadruplet times quick than standard RSA. 96IJRRAS 2 (2) ? February 2010 Subasree & Sakthivel ? Design of a New Security Protocol 2. 3 MD5 Algorithm MD52 consists of 64 of these operations, grouped in four rounds of 16 operations. F is a nonlinear function one function is used in each round. Mi denotes a 32 -bit close of the message input, and Ki denotes a 32 -bit constant, different for each operation. s is a shift value, which also varies for each operation1. MD5 processes a variable length message into a fixed -length output of 128 bits. The input message is broken up into chunks of 512-bit blocks the message is padded so that its length is divisible by 512.The padding works as follows first a single bit, 1, is appended to the end of the message. This is followed by as many zeros as are required to bring the length of the message up to 64 bits less than a multiple of 512. The re maining bits are filled up with a 64-bit integer representing the length of the original message9. The main MD5 algorithm operates on a 128 -bit state, divided into four 32-bit words, denoted A, B, C and D. These are initialized to certain fixed constants. The main algorithm then operates on each 512 -bit message block in turn, each block modifying the state.The bear on of a message block consists of four similar stages, termed rounds each round is composed of 16 similar operations based on a non -linear function F, modular addition, and left rotation. Many message digest functions have been proposed and are in use today. Here are just a few like HMAC, MD2, MD4, MD5, SHA, SHA-1. Here, we concentrate on MD5, one of the widely used digest functions. 3. HYBRID SECURITY PROTOCOL ARCHITECTURE It is desired to communicate data with high security. At present, various types of cryptographic algorithms provide high security to information on controlled networks.These algorithms are required to provide d ata security and users authenticity. This new security protocol has been designed for better security using a combination of both symmetric and asymmetric cryptographic techniques. depend 1 interbreeding Protocol computer architecture As shown in the figure, the Symmetric Key Cryptographic Techniques such as Elliptic Curve Cryptography, and MD5 are used to achieve both the Confidentiality and Integrity. The Asymmetric Key Cryptography technique, Dual RSA used for Authentication. The above discussed three primitives can be achieved with the help of this Security Protocol Architecture.The Architecture is as shown in the Figure 1. As shown in the figure, the Symmetric Key Cryptographic Techniques such as Elliptic Curve Cryptography, and MD5 are used to achieve bo th the Confidentiality and Integrity. The Asymmetric Key Cryptography technique, Dual RSA used for Authentication. 97 Subasree & Sakthivel ? Design of a New Security Protocol IJRRAS 2 (2) ? February 2010 The new Security Pr otocol has been designed for better security. It is a combination of both the Symmetric and Asymmetric Cryptographic Techniques.It provides the Cryptographic Primitives such as Integrity, Confidentiality and Authentication. The given plain text can be encrypted with the help of Elliptic Curve Cryptography, ECC and the derived cipher text can be communicated to the destination through any secured channel. Simultaneously, the Hash value is calculated through MD5 for the same plain text, which already has been converted into the cipher text by ECC. This Hash value has been encrypted with Dual RSA and the encrypted message of this Hash value also sent to destination. The intruders may try to hack the original information from the encrypted messages.He may be trapped both the encrypted messages of plain text and the hash value and he will try to decrypt these messages to get original one. He might be get the hash value and it is impossible to extract the plain text from the cipher text, because, the hash value is encrypted with Dual RSA and the plain text is encrypted with ECC. Hence, the message can be communicated to the destination with highly secured manner. The new hash value is calculated with MD5 for the received originals messages and then it is compared with decrypted hash message for its integrity.By which, we can ensure that either the origi nal text being altered or not in the communication medium. This is the primitive feature of this hybrid protocol. 4. RESULTS AND resultant 4. 1 Comparison of RSA and Dual RSA 1) The Public Key Algorithms, RSA and Dual-RSA have been implemented in VC++ and we got the following results. As shown in the Figure 2, the original message for communication is stored in MyFile. txt and its size is 547 Bytes, which is shown in the report file. Figure 2 Input File MyFile. txt Figure 3 shows that the project main menu, which consists of various features. They are i. RSA Encryption, ii.RSA Decryption, iii. Dual RSA Encryption, iv. Dual RSA Decryption, and v. Graph, which is used to compare the computational costs of both the RSA and Dual -RSA Figure 4 shows that RSA Encryption and Figure 5 shows that Dual RSA encryption. From the figure 6 it is clear that the RSA take one block at a time for encryption and decryption at a time. But the dual RSA take more time for encryption of two block at a time, but it take less time for decryption of two blocks. So, the RSA encryption and decryption time is greater than Dual RSA because Dual RSA perform the encryption and decryption operation for two blocks. 8 IJRRAS 2 (2) ? February 2010 Subasree & Sakthivel ? Design of a New Security Protocol Figure 3 Process of RSA and Dual RSA Encryption/Decryption Figure 4 RSA Encryption 99 Subasree & Sakthivel ? Design of a New Security Protocol IJRRAS 2 (2) ? February 2010 Figure 5 Dual RSA Encryption 5. 2 Performance analysis of RSA and Dual RSA Figure 6 RSA vs Dual RSA 100 IJRRAS 2 (2) ? February 2010 Subasree & Sakthive l ? Design of a New Security Protocol Figure 7 Computational costs of RSA vs Dual RSA Figure 6 shows that the Perfor mance Analysis of RSA vs Dual RSA.From this figure, it is clear that the hit computation time for Encryption and Decryption of Dual -RSA is less than that of ordinary RSA. From the Figure 7, it is observed that the total computation time for Encrypt ion and Decryption of RSA is 4314ms as compared with the total computation time for Encryption and Decryption of Dual RSA is 3203ms for the file size 547 Bytes. From the analysis it is clear that Dual RSA is better than RSA algorithm. So, for authentic ation we are issue to use Dual RSA. Dual RSA take two block for encryption and decryption simultaneously. . 3 Results of Hybrid protocol Architecture Here, we are using three different mode of operation. The sender, Receiver and Intruder. We have t o select the mode and process the information. The following figure represent the three different mode. Figure 8 Mode selec tion If the mode is the sender, then we have to provide the key val ue and messages in the specified location. Figure 9 Sender Mode hundred and one Subasree & Sakthivel ? Design of a New Security Protocol IJRRAS 2 (2) ? February 2010 Figure 10 shows that the Receiver received the sender message with the key.From the figure, it is noted that, the intruder also received the key and not the message. Because, the message is encrypted with ECC and key is encrypted by using Dual RSA. And also noted that, the intruder derived different key for decryption, which is akin to the original key. Even though the intruder got the key he cannot able to get the orig inal message because of Dual RSA. Because of Dual RSA we got two advantages one is the message cannot be decrypted and time required to perform the encryption and decryption operation less compare to RSA because Dual RSA perform encryption and decryption by two block at a time.The new Public Key Cryptographic algorithm, Dual RSA has b een developed for better performance in terms of computation costs and shop storage requirements. It is also called RSA -CRT, because it is used Chinese Remainder Theorem, CRT for its Decryption. From the output, it is noted that Dual -RSA improved the performance of RSA in terms of computation cost and computer storage storage requirements. It achieves parallelism. The CRT Decryption is achieved roughly ? times faster than original RSA. Figure 10 Secured communication of Hybrid Protocol 102 IJRRAS 2 (2) ? February 2010 Subasree & Sakthivel ?Design of a New Security Protocol 6. 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BIOGRAPHY Dr. S Subasree got Bachelor Degree from Madras university in 1991 and she done her post graduate degree from Bharathidasan Univeristy in 1995 and M. hil from Manonmaniam Sundaranar Univeristy in 2001. She done her M. Tech and Ph. D in SASTRA University in 2006 and 2009 respectively. She got 13 years teaching experience. Now she will be serving as a Senior Assistant Professor in SASTRA Univeristy, Tamil Nadu, India. She has create more than 15 papers in International and National Journals and Conferences. Her research area includes Network Security, High Performance Soft Computing Techniques, Communication Network, and B iometric Cryptography. Dr. N K Sakthivel got Bachelor Degree from Madras university in 1991 and she one her post graduate degree from Bharathidasan Univeristy in 1994 and M. phil from Bharathidasan Univeristy in 2000. She done her M. Tech and Ph. D in SASTRA University in 2004 and 2009 respectively. She got 15 years teaching experience. Now She will be serving as a Professor in SASTRA Univeristy, Tamil Nadu, India. She has published more than 18 papers in International and National Journals and Conferences. Her research area includes High Speed Communication Networks, Network Security, High Performance Computing, and Biometric Cryptography. 103