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ISBN: 378 - 26 - 138420 - 5
Enhanced Cryptography Algorithm for Providing Data Security Dr. K.Kiran Kumar, K.Kusuma Kavya, K.R.L.Sindhura Department of Information Technology, Bapatla Engineering College, Bapatla. Abstract: Information security is the process of protecting information. Due to enormous development in internet technology the security of data has now become a very important challenge in data communication network. One cannot send any confidential data in raw form from one machine to another machine as any hacker can intercept the confidential message. In this paper we have developed a new cryptography algorithm which is based on block cipher concept. In this algorithm we have used logical operations like XOR and shift operations which is used to increase security.
must consider many factors like: security, time and space complexity. A Simplified Model of Conventional Encryption
This paper is further divided into three sections. In section 2, we are presenting detailed description of Information security using cryptography and various algorithms. In section 3, we are presenting our proposed algorithm. In section 4, we have explained the proposed algorithm by taking an example of 128 bits (16 characters) and in section 5 we have conclusion.
Keywords:Information security, Encryption, Decryption, Cryptography. 1. Introduction The main feature of the encryption/ decryption program implementation is the generation of the encryption key. Now a days, cryptography has many commercial applications. The main purpose of the cryptography is used not only to provide confidentiality, but also to provide solutions for other problems like: data integrity, authentication, non-repudiation. Cryptography is the method that allows information to be sent in a secure form in such a way that the only receiver able to retrieve the information. However, it is very difficult to find out the specific algorithm, because we have already known that they
2. Information security using cryptography Here a newly developed technique named, “A new Symmetric key Cryptography Algorithm using extended MSA method: DJSA symmetric key algorithm” is discussed. In this a symmetric key method where we have used a random key generator for generating the initial key and the key is used for encrypting the give source file and we are using substitution method where we take 4 characters from any input file and then search the corresponding characters in the random key matrix file after getting the
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encrypted message they store the encrypted data in another file. To decrypt any file one has to know exactly what is the key and to find the random matrix theoretically. They apply method on possible files such as executable file, Microsoft word file, excel file, access database, FoxProfile, text file, image file, pdf file, video file, audio file, oracle database and they have found in all cases it giving 100% correct solution while encrypting a file and decrypting a file. In the following section we are going in detail. Here another newly developed technique named, “Effect of Security Increment to Symmetric Data Encryption through AES Methodology� is discussed. In this method they describe about symmetric cipher algorithm which is much more similar. The difference is that, Rijndael algorithm start with 128 bits block size, and then increase the block size by appending columns[10], whereas his algorithm start with 200 bits.
ISBN: 378 - 26 - 138420 - 5
Encryption Approach Used Here we are using symmetric encryption approach, and already we know that symmetric encryption approach is divided into two types: 1. Block cipher symmetric cryptography technique 2. Stream cipher symmetric cryptography. But here we are choosing block cipher type because its efficiency and security. In the proposed technique we have a common key between sender and receiver, which is known as private key. Basically private key concept is the symmetric key concepts where plain text is converting into encrypted text known as cipher text and is decrypted by same private key into plane text. The keys, in practice, represent a shared secret between two or more parties that can be used to maintain private information. Proposed Key Generation Steps
3. Proposed Algorithm 1. Create any private key of Size 16 characters. It will be varying from 16 to 64 characters. 2. We can choose any character from 0 to 255 ASCII code. 3. Use of 16*8 key that means 128 bits in length. 4. Divide 16 bytes into 4 blocks of KB1, KB2, KB3 and KB4. 5. Apply XOR operation between KB1 and KB3.Results will store in new KB13. 6. Apply XOR operation between KB2 and KB13.Results will store in new KB213. 7. Apply XOR operation between KB213 and KB4. Results will store in new KB4213. ( KB:KEY BLOCK)
In this section we are presenting a new block based symmetric cryptography algorithm, and using a random number for generating the initial key, where this key will use for encrypting the given source file using proposed encryption algorithm. Basically In this technique a block based substitution method will use. In the present technique I will provide for encrypting message multiple times. The proposed key blocks contains all possible words comprising of number of characters whose ASCII code is from 0 to 255 in a random order. The pattern of the key blocks will depend on text key entered by the user. To decrypt any file one has to know exactly what the key blocks is and to find the random blocks theoretically one has to apply 2^256 trial run and which is intractable.
Steps for proposed Algorithm 1. Initially select plain text of 16 bytes.
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2. Apply XOR operation between key (KB4213) and plain text block. Result will store in CB1. 3. Apply right circular shift with 3 values. Result will store in CB2. 4. Apply XOR operation between CB2 and KB2. 5. Result will store in new CB3. 6. Apply XOR operation between CB3 and KB4. Result will store in CB4.
KB 13: 00011110 00011100
ISBN: 378 - 26 - 138420 - 5
00010100
11110011
Step:3 Apply the EX-OR operation between KB2 & KB13 KB2: 10000100 01110110 01101001 KB13:00011110 00010100 00011101 KB213: 10011010 01100010 01110100
(CB:CIPHER BLOCK) 4. Implementation example of the Proposed Algorithm
01100101 11110011 10010110
Step:4 Encryption Method Apply the EX-OR operation between KB4 & KB213:
Key Generation:
KB213:10011010 01100010 10010110 01110100 KB4: 01101001 01101001 10000010 10000011 KB4213: 11110011 00001011 00010100 11110111
Step:1 1.Take the 16 characters plain text 2.Plain text: BAPATLAENGINEERS 3. Divide the key in to 4 blocks BAPA KB 1
TLAE KB2
NGIN KB 3
EERS The obtained key is: 11110011 00001011 11110111
KB 4
00010100
Step:2 Encryption: Apply the EX-OR operation between KB1 & KB3
Step:1
BAPA KB1
Apply the EX-OR operation between KB 4213 & KB1:
NGIN KB3
BAPA- 66 65 80 65 NGIN- 78 71 73 78 KB1: 01100110 01100101 KB3: 01111000 01111000
KB4213: 11110011 00001011 11110111 KB1: 01100110 01100101 01100101 CB1: 10010101 01101110 10010010
01100101 10000000 01110001
01110011
00010100 10000000 10010100
Step:2
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P1: 01100110 01100101
Apply right circular shift with 3bits of CB1. Result will store in new CB2. CB2: 01010010 10010010
10101101
10000000
10101101
11010010
CB 2: 01010010 10101101 10010010 CB 3: 11010110 11011011 11111011 P2: 10000100 01110110 01101001
01110110
01100101
Step:3
11011011
10110111
Apply the EX-OR operation between CB3 & CB4:
Apply the EX-OR operation between CB2 & KB2:
10110111
CB3: 11010110 11111011 CB4: 10111111 01111000 P4: 01101001 10000011
10000010
Step:4
00110101
Plain text 3 is : Apply the EX-OR KB4321 & P4
Step:4 Apply the EX-OR operation between CB3 & KB4: CB3: 11010110 11111011 KB4: 01101001 10000011 CB4: 10111111 01111000
01100101
Step:2 Apply the EX-OR operation between CB2& CB3:
11010010
Step:3
CB2: 01010010 10010010 KB2: 10000100 01101001 CB3: 11010110 11111011
ISBN: 378 - 26 - 138420 - 5
11011011 01101001 10110010
Now CB1, CB2, CB3, CB4 are the cipher blocks respected to KEY1, KEY2, KEY3, KEY4
Step:1 Apply the EX-OR KB4213 & CB1
operation
KB4213: 11110011 00001011 11110111 CB1: 10010101 01101110 10010010
between
10110111 01100101
11011011
10110111
10110010
00110101
01101001
10000010
operation
KB4213: 11110011 00001011 11110111 P4: 01101001 01101001 10000011 X1: 10011010 1100010 01110100
Decryption Method:
11010010
between
00010100 10000010 10010110
Step:5 Apply the EX-OR operation between X1 & P2
00010100 10010100
X1: 110011010 01110100
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01100010
10010110
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P2: 10000100 01101001 X2: 00011110 00011101 Step:6
01110110
01100101
6. References
00010100
11110011
[1] Dripto Chatterjee, Joyshree Nath, Suvadeep Dasgupta, Asoke Nath “A new Symmetric key Cryptography Algorithm using extended MSA method: DJSA symmetric key algorithm” published in 2011 International Conference on Communication Systems and Network Technologies, 978-07695-4437-3/11 $26.00 © 2011 IEEE. [2] Yan Wang and Ming Hu “Timing evaluation of the known cryptographic algorithms “2009 International Conference on Computational Intelligence and Security 978-0-7695-3931-7/09 $26.00 © 2009 IEEE DOI 10.1109/CIS.2009.81. [3] Symmetric key cryptography using random key generator, A.Nath, S.Ghosh, M.A.Mallik, Proceedings of International conference on SAM-2010 held at Las Vegas(USA) 12-15 July,2010, Vol-2,P-239244. [4] Data Hiding and Retrieval, A.Nath, S.Das, A.Chakrabarti, Proceedings of IEEE International conference on Computer Intelligence and Computer Network held at Bhopal from 26-28 Nov, 2010. [5] Neal Koblitz “A Course in Number Theory and Cryptography” Second Edition Published by Springer-Verlag. [6] T Morkel, JHP Eloff “ ENCRYPTION TECHNIQUES: A TIMELINE APPROACH” published in Information and Computer Security Architecture (ICSA) Research Group proceeding. [7] Text book William Stallings, Data and Computer Communications, 6eWilliam 6e 2005. [8] [Rijn99]Joan Daemen and Vincent Rijmen, AES submission document on Rijndael, Version 2, September 1999.
Apply the EX-OR operation between X2 & P1 X2: 00011110 00011101 P1: 01100110 01100101 P3: 01111000 01111001
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00010100
11110011
01100101
10000000
01110001
01110011
Here P1,P2,P3,P4 are the plain text’s with respect to key blocks KB1,KB2,KB3,KB4. If we want to get P3, we are going to use KB4321,P4,P2,P1. Decrypted Text is: BAPATLAENGINEERS 5. Conclusion In this paper we have specified a new algorithm based on block cipher principle. In this algorithm we have used logical operations like XOR and shift operations which is used to increase security. The algorithm is explained with the help of an example clearly. Our method is essentially block cipher method and it will take less time if the file size is large. The important thing of our proposed method is that it is almost impossible to break the encryption algorithm without knowing the exact key value. We propose that this encryption method can be applied for data encryption and decryption in any type of public application for sending confidential data.
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