IAETSD

1. 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.
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
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.
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
76
INTERNATIONAL CONFERENCE ON CURRENT INNOVATIONS IN ENGINEERING AND TECHNOLOGY
INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT
ISBN: 378 - 26 - 138420 - 5
www.iaetsd.in

2. 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.
3. Proposed Algorithm
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.
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
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)
Steps for proposed Algorithm
1. Initially select plain text of 16 bytes.
77
INTERNATIONAL CONFERENCE ON CURRENT INNOVATIONS IN ENGINEERING AND TECHNOLOGY
INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT
ISBN: 378 - 26 - 138420 - 5
www.iaetsd.in

3. 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.
(CB:CIPHER BLOCK)
4. Implementation example of the
Proposed Algorithm
Encryption Method
Key Generation:
Step:1
1.Take the 16 characters plain text
2.Plain text: BAPATLAENGINEERS
3. Divide the key in to 4 blocks
BAPA TLAE NGIN EERS
KB 1 KB2 KB 3 KB 4
Step:2
Apply the EX-OR operation between KB1
& KB3
BAPA NGIN
KB1 KB3
BAPA- 66 65 80 65
NGIN- 78 71 73 78
KB1: 01100110 01100101 10000000
01100101
KB3: 01111000 01110001 01110011
01111000
KB 13: 00011110 00010100 11110011
00011100
Step:3
Apply the EX-OR operation between KB2
& KB13
KB2: 10000100 01110110 01100101
01101001
KB13:00011110 00010100 11110011
00011101
KB213: 10011010 01100010 10010110
01110100
Step:4
Apply the EX-OR operation between KB4
& KB213:
KB213:10011010 01100010 10010110
01110100
KB4: 01101001 01101001 10000010
10000011
KB4213: 11110011 00001011 00010100
11110111
The obtained key is:
11110011 00001011 00010100
11110111
Encryption:
Step:1
Apply the EX-OR operation between KB
4213 & KB1:
KB4213: 11110011 00001011 00010100
11110111
KB1: 01100110 01100101 10000000
01100101
CB1: 10010101 01101110 10010100
10010010
Step:2
78
INTERNATIONAL CONFERENCE ON CURRENT INNOVATIONS IN ENGINEERING AND TECHNOLOGY
INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT
ISBN: 378 - 26 - 138420 - 5
www.iaetsd.in

4. Apply right circular shift with 3bits of CB1.
Result will store in new CB2.
CB2: 01010010 10101101 11010010
10010010
Step:3
Apply the EX-OR operation between CB2
& KB2:
CB2: 01010010 10101101 11010010
10010010
KB2: 10000100 01110110 01100101
01101001
CB3: 11010110 11011011 10110111
11111011
Step:4
Apply the EX-OR operation between CB3 &
KB4:
CB3: 11010110 11011011 10110111
11111011
KB4: 01101001 01101001 10000010
10000011
CB4: 10111111 10110010 00110101
01111000
Now CB1, CB2, CB3, CB4 are the cipher
blocks respected to KEY1, KEY2, KEY3,
KEY4
Decryption Method:
Step:1
Apply the EX-OR operation between
KB4213 & CB1
KB4213: 11110011 00001011 00010100
11110111
CB1: 10010101 01101110 10010100
10010010
P1: 01100110 01100101 10000000
01100101
Step:2
Apply the EX-OR operation between CB2&
CB3:
CB 2: 01010010 10101101 11010010
10010010
CB 3: 11010110 11011011 10110111
11111011
P2: 10000100 01110110 01100101
01101001
Step:3
Apply the EX-OR operation between CB3
& CB4:
CB3: 11010110 11011011 10110111
11111011
CB4: 10111111 10110010 00110101
01111000
P4: 01101001 01101001 10000010
10000011
Step:4
Plain text 3 is :
Apply the EX-OR operation between
KB4321 & P4
KB4213: 11110011 00001011 00010100
11110111
P4: 01101001 01101001 10000010
10000011
X1: 10011010 1100010 10010110
01110100
Step:5
Apply the EX-OR operation between X1 &
P2
X1: 110011010 01100010 10010110
01110100
79
INTERNATIONAL CONFERENCE ON CURRENT INNOVATIONS IN ENGINEERING AND TECHNOLOGY
INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT
ISBN: 378 - 26 - 138420 - 5
www.iaetsd.in

5. P2: 10000100 01110110 01100101
01101001
X2: 00011110 00010100 11110011
00011101
Step:6
Apply the EX-OR operation between X2
& P1
X2: 00011110 00010100 11110011
00011101
P1: 01100110 01100101 10000000
01100101
P3: 01111000 01110001 01110011
01111001
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.
6. References
[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, 978-0-
7695-4437-3/11 $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-239-
244.
[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.
80
INTERNATIONAL CONFERENCE ON CURRENT INNOVATIONS IN ENGINEERING AND TECHNOLOGY
INTERNATIONAL ASSOCIATION OF ENGINEERING & TECHNOLOGY FOR SKILL DEVELOPMENT
ISBN: 378 - 26 - 138420 - 5
www.iaetsd.in