Open Access  Subscription or Fee Access

### Block based Data Encryption and Decryption using Number System Logic

Ayan Banerjee, Dr. Pranam Paul

#### Abstract

Cryptography is the automated (or algorithmic) method in which security goals are accomplished. Typically, when we say “crypto algorithm” we are discussing an algorithm meant to be executed on a computer. These algorithms operate on messages in the form of groups of bits.

Here we introduced a Block based symmetric key encryption algorithm, which is based on simple mathematical operation. In this algorithm encryption is done on binary file so it can be applicable for any type of data such a text as well as multimedia data [3]-[9]. For encryption a key is to be generated. Key length and bit stream is chosen at random. At first, the plain text has been converted into its binary form and then the binary file is divided into some blocks. The block length is our key and it’s choosing randomly.

Our algorithm is based on the following method:--

If the sum of each digit of a number is subtracted from that number, then the result is obviously divisible by a particular number [5]-[8]. This is the foundation of our algorithm.

#### Keywords

Cipher Text, Cryptography, Decryption, Encryption, Plain Text, Symmetric Key.

PDF

#### References

William Stallings,”Cryptography and network securityprinciples and practices”, 4th edition, Pearson Education, Inc.,publishing as Prentice Hal, 2006.

Pranam Paul, Saurabh Dutta, A K Bhattacharjee,”AnApproach to ensure Security through Bit-level Encryption with Possible Lossless Compression”, International Journal ofComputer Science and Network Security”, Vol. 08, No. 2, pp. 291 – 299, 2008.

Sanjit Mazumdar, Sujay Dasgupta, Prof.(Dr) PranamPaul, ”Implementation of Block based Encryption at Bit-Level”, International journal of Computer Science andNetwork Security, Vol. 11, No.2, pp. 18-23, 2011.

Sujay Dasgupta, Sanjit Mazumdar, Prof.(Dr) Pranampaul, “Implementation of Information Security based on Common Divison”, International journal of Computer Science andNetwork Security, Vol. 11, No.2,pp. 51-53, 2011.

http://en.wikipedia.org/wiki/Symmetric-key_algorithm

AsokeNath, Saima Ghosh, Meheboob Alam Mallik, ”Symmetric Key Cryptography using Random keyGenerator”, Proceeding of International conference on securityand management(SAM’10” held at Las Vegas, USA Jull 12-15,2010), P-Vol-2, pp. 239-244,2010.

Pranam Paul, Saurabh Dutta, “An Enhancement ofInformation Security using Substitution of Bits Through PrimeDetection in Blocks”, Proceeding of National Conference onRecent Trends in information Systems(ReTIS-06), Organizedby IEEE Gold Affinity Group, IEEE Calcutta Section, Computer Science & Engineering Department, CMATER &SRUVM Project-Jadavpur University and Computer Jagat.

Oded Goldreich, “Foundation of Cryptography (A primer)”, July 2004.

Bruce Schneier, “Applied Cryptography”, ISBN 0-471-12845-7

John Talbot, Dominic Welsh; “Complexity and Cryptography An introduction”. ISBN-10: 0521852315

Denise Sutherland, Mark Koltko-Rivera “Cracking Codes and Cryptograms For Dummies”,; ISBN: 978-0-470-59100-0;October 2009

Alfred J. Menezes, Paul C. van Oorschot and Scott A. Vanstone “Handbook of Applied Cryptography”; CRC Press; ISBN: 0-8493-8523-7

WILLIAM 'F. FRIEDMAN; “MILITARY CRYPTANALYSIS, Pa:r.t I, MONOALPHABETIC SUBSTITUTION SYSTEMS”

Henk C.A. van Tilborg, Sushil Jajodia; “Encyclopedia of Cryptography and Security”, 2nd edition; 2011; ISBN: 144195905X

Wenbo Mao; “Modern Cryptograph”..

Wels Chenbach; “Cryptography in C and C++”.

### Refbacks

• There are currently no refbacks.