Providing Cryptographic Security Using LDPC Encoder and Stopping Sets

International Journal of Emerging Technology and Advanced Engineering

632

Providing Cryptographic Security Using LDPC

Encoder and Stopping Sets

1

Kiran Sayalekar, 2Bhushan Sonawane, 3Mayur Laddha, 4Rahul Shihare Student, SITRC , Nashik

Abstract- In this paper we are describing how the secure communication can be achieved by using LDPC and stopping sets in data transmission process. It Emphasizes that the LDPC encoder and Stopping sets are been used for encrypting and decrypting the message respectively. By using this technique we achieved error free and secure communication. It also prevent the unauthorized access and possibility of overcoming the eavesdropper activity. Coding for cryptography using stopping set is the technique to encrypt and decrypt the message to give high security to our data. It has been used in many fields like defense services, scientific and space communication for confidential data. The module called as stopping set is introduced to decrypt the data in error free form for receiver.

Keywords- Cryptography, Encoder, Decoder, LDPC, Stopping sets, Eavesdropper.

I. INTRODUCTION A. Cryptography and its Need

Nowadays hacking is big issue occurred recently in computer science. So to prevent unauthorized access through hacking we are using cryptography with additional technique known as LDPC encoder and Stopping sets to make the basic cryptographic process more secure. Coding for Cryptography using Stopping Sets are the technique to encrypt and decrypt the message to give high security to our data. Cryptography has been developed for the purpose to give security to data from unauthorized user. The module called as a Stopping Sets is introduced to Decrypt the message for receiver.Many cryptosystems used today achieve security by simple encryption and decryption using some algorithm and mathematical calculation but nowadays this is also not sufficient to provide security to the data. So we are introducing the cryptography with LDPC encoder and stopping sets in order to provide a complete security solution to the data at the process of transmission . First, it is assumed that the attacker has limited resources to confront the problem, even if those resources are state of the art. Second, it is assumed that the attacker uses attacks which are publicly known, even though a better attack may exist.

B.Main Contributions

The aim of this paper is to provide the combined security due to cryptography and channel coding, thus providing a more complete security solution. To accomplish this goal, we are making the use of LDPC encoder and Stopping sets to encrypt and decrypt the error free messages that will be transmitted through the secure channel.

C.Related Work.

International Journal of Emerging Technology and Advanced Engineering

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Schemes have been presented in [8] and [9] which achieve the secrecy capacity under the condition in (1), although these schemes only offer secrecy for degraded wiretap channels

.

II.MATHEMATICAL MODULE &STATE DIAGRAM

S0:-SENDER

S1:-ENCODE

S2:-LDPC

S3:-STOPPING SETS

S4:-DECODER

S5:-RECEIVER

1.The sequential algorithm will execute the function SEND 1 time to get the required results.The function may contain source(sender),destination(receiver) key.

2.The sequential algorithm will execute the function ENCODE 1 time to get the required results.The function may contain key,message.

3.The sequential algorithm will execute the function DECODE 1 time to get the required results.The function may contain key,message.

4.The sequential algorithm will execute the function RECEIVE 1 time to get the required results.The function may contain key,message(Cipher text).

5.The sequential algorithm will execute the function LDPC n times to get the required results.The function may contain key,message.

2.1 Definitions and assumptions:

Let S be the system such that S be a encrypted communication channel.

S={Message(M),Sender(X),Receiver(Y),Hacker(H),Key( K),encrypted message i.e. ciphertext(C)}

Where

M={M0,M1,M2……..Mn}

X={X0}

Y={Y0}

H={H1,H2,H3,….,Hn}

K={K1,K2}

C={C0,C1,C2….Cn}

2.2 Activity:

In this chapter we describe the functions of each module.

For example:-

1.)F{M0,M1,M2,…,Mn}→{C0,C1,C2,..Cn€C}

2.)F{H0}→{C0,C1,C2,…Cn}€C

F{H}→{C}

3.)F{X0}→{C0,C1,C2,…Cn}€C}

F{X}}→{C}

4.)F{Y0}→{M0,M1,M2,…Mn}€M}

F{M}}→{M}

5.)F{K0}→{M0,M1,M2,…Mn}€M}

F{K}→S{M}

International Journal of Emerging Technology and Advanced Engineering

634 III. MAIN ALGORITHM

1.Start

2. Sending the message

3. Encode the message by LDPC encoder.

4. Transmit the message to the decoder.

5. if(message=error free)

Message decode successfully;

Else

Acknowledgement to the sender

6. Trnasmit the message to receiver.

7. Repeat step 5.

8. Message hacked by the eavesdropper.

9. Captured message is in the form of binary.

10. LDPC cannot permit the eavesdropper.

11. Message transmitted successfully.

12. Stop.

3.1 Encoder

In this fig, the encoding process is shown by using the LDPC encoder. The following principles are addressed in the design of this encoder.

• Bits of M are hidden from immediate access in the decoded words using nonsystematic LDPC codes. • Message contents are encrypted and are assigned a unique value.

• The encrypted message is then stored inside the buffer for the transmission.

• Bits from encoded blocks are interleaved amongst several transmitted packets so that a single erased packet results in erasures in many encoded blocks of data.

3.1.1 Algorithm(Encoder)

1. Start

2. Message is transferred to LDPC Encoder 3. The code is hidden by LDPC Encoder

4. Debugging the errors in the physical layer of network 5. The message error is corrected by LDPC (Punctured block)

6. Packets are converted into several block of data. 7. These blocks are stored in buffer.

8. This blocks are converted into packets by interleaver. 9. Again packets are forwarded.

10 .Stop.

3.2 Decoder:-

3.2.1 Decoder For Legitimate Users

The message is retrieved from the buffer for decoding.Decoding process is shown pictorially in Fig. 3. Once all packets are obtained in Y , the bits are deinterleaved back into their intentionally punctured code words ˜ P. The MP decoder is then guaranteed to decode the complete message in linear time with the block length to obtain ˜B , and the inverse of the scrambling matrix is applied to the systematic decoded bits using (10) to obtain ˜M . Once all packets are known, this decoder guarantees that ˜M = M.This assures that original message is been received.

3.2.3 Algorithm (Decoder)

1.Start

2.Packets that are stored in buffer are sent to Drinterleaver

3.These packets are decoded.

4.Once all packets are known then decoder guarantees .

5.~M=M where M=Message

International Journal of Emerging Technology and Advanced Engineering

635

Fig .4.:Main Block diagram of Data Transmission

IV.CONCLUSION

In conclusion, we have presented the process of secure data transmission from sender to receiver by using the two dynamic algorithm i.e. LDPC for encoder and STOPPING SET for decoder. These algorithm help us to establish a secure and error free communication between two entities. Also we have presented use of LDPC algorithm for error correction, and stopping set algorithm for decode the error free message. This process help us to keep the message content secret even if it is hack by the eavesdropper.

ACKNOWLEDGMENTS

We are thankful to SITRC College of Engineering for giving us an opportunity to complete the Paper successfully. Also we are thankful to Principal of SITRC College of Engineering, Prof. Dr.S.T.Gandhe for their kind co-operation in completion of this paper .

We place a deep sense of appreciation and regard to our Project guide Prof. Tushar B. Kute and Co-Guide Prof. Vivek Waghmare giving us all possible help and suggestions to give our Project a perfect shape. We would also like to thank our Project co-ordinator Prof. Bhushan Chaudhari for providing all the assistance and facilities which were vital in completing this Project.

Last but not least we have to express our feelings towards all staff members of SITRC College of Engineering, Nashik and special thanks to our college and friends for their moral support and help.

R

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