SK Sarif Hassan*1, Pabitra Pal Choydhury2 and Soumalya Ghosh3.
Received: April 27, 2017 Published: May 25, 2017
Corresponding author: SK Sarif Hassan, Department of Mathematics, Pingla Thana Mahavidyalaya, Malligram, Paschim Medinipur, West Bengal, India
DOI: 10.26717/BJSTR.2017.01.000107
This paper presents a spatial encryption technique for secured transmission of data in networks. The algorithm is designed to break the ciphered data packets into multiple data which are to be packaged into a spatial template. A secure and efficient mechanism is provided to convey the information that is necessary for obtaining the original data at the receiver-end from its parts in the packets. An authentication code (MAC) is also used to ensure authenticity of every packet.
Keywords: Data Packet; Clastal W; Star model and Key packet
Security of network communications is the most important issue in the world. Information transactions related to banks, credit cards, and government policies are transferred from place to place with the help of network transmission. The high connectivity of the World Wide Web (WWW) has left the world ‘open’. Such openness has resulted in various networks being subjected to multifarious attacks from vastly disparate sources, many of which are anonymous and yet to be discovered. This growth of the WWW coupled with progress in the fields of e-commerce and the like has made the security issue even more important [1-5].
In practice, in a computer network, data is transferred across the nodes in the form of packets of fixed or variable sizes. In usual practice, the implementation is done by some secured algorithms at the application level on the data and the enciphered data is packetized at lower levels (in the OSI architecture) and sent. Any intruder able to obtain all the packets can then obtain the enciphered data by appropriately ordering the data content of each of these packets. Then, efforts can be made to break the secured algorithm used by the sender. In the process of transmission, if it is possible to prevent any information release as to the structure of the data within the packets, an intruder would know neither the nature of the data being transferred nor the ordering of the content from different packets. This is what our algorithm achieves by using a genomical spatial envelope. We have used genomic steganography in enhancing the security in the algorithm.
We use the concept of Message Authentication Code (MAC) as suggested in [Rivest, 1998] to authenticate messages. For a packet of data, the MAC is calculated as a function of the data contents, the packet sequence number and a secret key known only to the sender and the receiver, and then it is appended to the packet. On receiving a packet, the receiver first computes the MAC using the appropriate parameters, and then performs a check with the MAC attached to the packet. If there is no match, then the receiver knows that the packet has been tampered with. A detailed explanation is provided in the next section.
Let the size of an encrypted packet data in a network be denoted as PS. PS has a value of 1024- bits or 4096- bits typically. The packet data is now to break arbitrarily in N parts. These N parts are to be inserted to into the blank envelope. The size of total data, number N and the nucleotide sequences with which alignment is to be performed using ClastalW is communicated between the receiver and sender using a secure channel. The packet data size is represented in number of bits required to represent the size of total data sent .We use (N-1)*2 bits (or N-1 ATGC’s) to represent packet data number [6,7].
In receiver end the following steps are required to decrypt the message:
(A) Demonstration of the Algorithm:
The plain text (P) is
I AM SUGATA SANYAL
The binary text (B) corresponding to (P):
0100100100100000010000010100110100100000010100110101010101000111010000010101010 0010000010010000001010 0110100000101001110010110010100000101001100 (Size is 144)
The cipher text (C) corresponding to (B) The crypto map is T (0) =1; T (1) =0.
1011011011011111101111101011001011011111101011001010101010111000101111101010101110 1111101101111110101 1001011111010110001101001101011111010110011
We have to transfer the each data into its ATCG from by the following transformation:
s (00) = A; s (01) = C; s (10) = G and s (11) = T
The transformed text (E) corresponding to (C) is:
GTCGTCTTGTTGGTAGTCTTGGTAGGGGGTGAGTTGGGGTGTTGTCTTGGTAGTTGGTACGGCGGTTGGTAT
Now we need to break the data E into arbitrarily N parts.
E1=000001: GTCGTCTTGTTGGTAGTCTTGGT (Size 23)
E2:AGGGGGTGAGTTGGGGTGTTGTCTTGGTAGTTGGTACGGCGGTTGGTAT (Size 49)
E21=001001: AGGGGGTG (Size 8)
E22: AGTTGGGGTGTTGTCTTGGTAGTTGGTACGGCGGTTGGTAT (Size 41)
E221=101001: AGTTGGGGT (Size 9)
E222=101010: GTTGTCTTGGTAGTTGGTACGGCGGTTGGTAT (Size 32)
Suppose we take the break data set as { E1, E21, E221, E222}
Now we add packet size (size of data and size of packet number) at the starting of each packet.
Since our data size before packet formation is 144 which can be represented in (10010000) 8 bits we use a 8 bits (4 ATGC’s) representation of packet size.
Sizes of each packet are given below:
E1: 26 (size of packet + size of packet number=23+3)
(26)10=(00011010)2
Using crypto map we get size as 11100101
Using s size is represented as TGCC
E21: 11 (size of packet + size of packet number=8+3)
(11)10= (00001011)2
Using crypto map we get size as 11110100
Using s size is represented as TTCA
E221: 12 (size of packet + size of packet number=9+3)
(12)10= (00001100)2
Using crypto map we get size as 11110011
Using s size is represented as TTAT
E222: 35 (size of packet + size of packet number=32+3)
(35)10= (00100011)2
Using crypto map we get size as 11011100
Using s size is represented as TCTA
Now we need to packetize the above data into star model (OR1D2, OR1D4 and OR1D5) ….
Note that we need to send the packet number along with this data packet. We insert the data content followed by the packet number.
Therefore the data packets are as follows:
DE000001: (TGCC) GTCGTCTTGTTGGTAGTCTTGGT (AAC)
ATGGATGGAGTGAACCAGAGTGACCGTTCACAGTTCCTTCTCCTGGGGAT
GTCAGAGAGTCCTGAGCAGCAGCTGATCCTGTTTTGGATGTTCCTGTCCA
TGTACCTGGTCACGGTGCTGGGAAATGTGCTCATCATCCTGGCCATCAGC
TCTGATTCCCTCCTGCACACCCCCTTGTACTTCTTCCTGGCCAACCTCTC
CTTCACTGACCTCTTCTTTGTCACCAACACAATCCCCAAGATGCTGGTGA
ACGTCCAGTCCCATAACAAAGCCATCTCCTATGCAGGGTGTCTGACACAG
CTCTACTTCCTGGTCTCCTTGGTGTCCCTGGACAACCTCATCCTGGCGGT
GATGGCGTATGATCGCTATGTGGCCAACTGCTGCCCCCTCCACTAGTCCA
CAGCCATGAGCCCTTTGCTCTGTGTCTTGCTCCTTTCCTTGTGTTGGGAA
CTCTCAGTTCTCTATGGCCTCGTCCACACCTTCCTCGTGACCAGCGTGAC
CTTCTGTGGGACTGGACAAATCCACTACTTCTTCTGTGAGATGTAATTGC
TGCTGTGGATGGCATGTTCCAACAGCCATATTAATCACACAGGGGTGATT
GCCACTGGCTGCTTCATCTTCCTCACACCCTTGGGTTTCATGAACATCTC
CTATGTACGTATTGTCAGACCCATCCTATAAATGCCCTCCGTCTCTAAGA
AATACAAAGCCTTCTCTACCTGTGCCTCCCATTTGGGTGTAGTCTCCCTC
TTATATGGGATGCTTCATATGGTATACCTTGAGCCCCTCCATACCTACTC
GATGAAGGACTCAGTAGCCACAGTGATGTATGCTGTGCTGACACCCATGA
TGAATCCGTTCATCTACAGACTGAGGAACAATGACATGCATGGGGCTCTG
GGAAGACTCCTATGAATACGCTTTAAGAGGCTCATA
DE21=001001: (TTCA) AGGGGGTG (AGC)
ATGGATGGAGTTAACCAGAGTGACAAGTCAGAGTTCCTTCTCCTGGGGAT
GTCAGAGAGTCCTGAGCAGCAGCGGATCCTGTTTTGGATGTTCCTGTCCA
TGTACCTGGTCACGGTGGTGGGAAATGTGCTCATCATCCTGGCCATCAGC
TCTGATTCCCTCCTGCACACCCCCGTGTACTTCTTCCTGGCCAACCTCTC
CTTCACTGACCTCTTCTTTGTCACCAACACAATCCCCAAGATGCTGGTGA
ACATCCAGTCCCAGAACAAAGCCATCTCCTATGCAGGGTGTCTGACACAG
CTCTACTTCCTGGTCTCCTTGGTGCCCCTGGACAACCTCATCCTGGCAGT
GATGGCTTATGAGCGCTATGTGGCCACCTGCTGCCCCCTCCACTAATGCA
CAGCCATGAGCCCTAGGCTCTGTTTCTTCCTCCTATCCTTGTGTTGGGCT
CTGTCAGTTCTCTATGGCCTCCTGCACACCATCCTCTTGACCAGGGTGAC
CTTCTGTGGGACGTGATAAATCCACTACATCTTCTGTGAGATGTACCTAT
TGCTGAGGTTGGCATGTTCCAACAGCCACATTAGTCACACAGAGGTGATT
GCCACGGGCTGCTTCATCTTCCTCAGACCCTTCGGTTTCATGAACATCTC
CTATGTACGTATTGTCAGAGCCATCCTCATAATACCCTCAGTCTCTAAGA
AATACAAAACCTTCTCTACCTGTGCCTCCCATTTGGGTGGGGTCTCCCTC
TTATATGGGAAACTTGGTATGGTCTACCTACAGCCCCTCCATACCTACTC
AATGAAGGACTCAGTAGCCACAGTGATGTATGCTGTGCTGACACCAATGA
TGAAACCTTTCATCTACAGGCTGAGGAACAACGACATGCATGGGGCTCAG
GGAAGAGTCCTAATAAAACGCTTTCAGAGGCTTAAA
DE221=101001: (TTAT) AGTTGGGGT (GGC)
ATGGATGGAGTTAACCAGAGTGAATAGTCATAGTTCCTTCTCCTGGGGAT
TTCAGAGAGTCCTGAGCAGCAGCGGATCCTGTTTTGGATGTTCCTGTCCA
TGTACCTGGTCACGGTGGTGGGAAATGTGCTCATCATCCTGGCCATCAGC
TCTGATTCCCGCCTGCACACCCCCGTGTACTTCTTCCTGGCCAACCTCTC
CTTCACTGACCTCTTCTTTGTCACCAACACAATCCCCAAGATGCTGGTGA
ACTTCCAGTCCCAGAACAAAGCCATCTCCTATGCAGGGTGTCTGACACAG
CTCTACTTCCTGGTCTCCTTGGTGGCCCTGGACAACCTCATCCTGGCCGT
GATGGCATATGATCGCTATGTGGCCAGCTGCTGCCCCCTCCACTAATGCA
CAGCCATGAGCCCTATGCTCTGTGTCTTCCTCCTATCCTTGTGTTGGGTG
CTATCTGTGCTCTATGGCCTCCTACTCACCGTCCTCCTGACCAGAGTGAC
CTTCTGTGGGACTGGACAAATCCACTACTTCTTCTGTGAGATGTACCTCA
TGCTGAGGTTGGCATGTTCCAACAACCAAATAATTCACACAGAGTTGATT
GCCACAGGCTGCTTCATCTTCCTCATGCCCTTCGGATTCTTGAGCACATC
CTATGTACGTATTGTCAGACCCATCCTATGAATCCCCTCAGTCTCTAAGA
AATACAAAACCTTCTCTACCTGTGCCTCCCATTTGGGTGGCGTCTCCCTC
TTATATGGGATGCTTATTATGGTGTACCTCAAGCCCCTCCATACCTACTC
TATGAAGGACTCAGTAGCCACAGTGATGTATGCTGTGGTGACACCTATGA
TGAAACCGTTCATCTACAGGCTGAGGAACAATGACATGCATGGGGCTCTG
GGAAGAATCCTATGCAAACCCTTTTAGAGGCAAATA
DE222=101010: (TCTA) GTTGTCTTGGTAGTTGGTACGGCGGTTGGTAT (GGG)
ATGGATGGAGTCAACCAGAGTGATAGTTCATAGTTCCTTCTCCTGGGGAT
GTCAGAGAGTCCTGAGCAGCAGCTGATCCTGTTTTGGATGTTCCTGTCCA
TGTACCTGGTCACGGTGCTGGGAAATGTGCTCATCATCCTGGCCATCAGC
TCTGATTCCCTCCTGCACACCCCCTTGTACTTCTTCCTGGCCAACCTCTC
CTTCACTGACCTCTTCTTTGTCACCAACACAATCCCCAAGATGCTGGTGA
ACGTCCAGTCCCAGAACAAAGCCATCTCCTATGCAGGGTGTCTGACACAG
CTCTACTTCCTGGTCTCCTTGGTGTCCCTGGACAACCTCATCCTGGCAGT
GATGGCGTATGATCGCTATGTGGCCATCTGCTGCCCCCTCCACTAGGTCA
CAGCCATGAGCCCTACGCTCTGTGTCTTGCTCCTCTCCTTGTGTTGGGGG
CTTTCTGTGCTCTATGGCCTCGTTCACACCTTCCTCGTGACCAGGGTGAC
CTTCTGTGGGGCATGAGACATCCACTACATCTTCTGTGATATGTAGCTCA
TGCTGAGGTTGGCATGTTCCAACAGCCAAATTATTCACACAGCGCTGATT
GCCACCGGCTGCTTCATCTTCCTCATGCCCTTAGGTTTCATGATCAGCTC
CTATGTACGTATTGTCAGACCCATCCTTCAAATCCCCTCAGTCTCTAAGA
AATACAAAACCTTCTCCACCTGTGCCTCCCATTTGGGTGTAGTCTCCCTC
TTATATGGGAGTCTTCTTATGGTATACCTAGAGCCCCTCCATACCTACTC
ATTGAAGGACTCAGTAGCCACAGTGATGTATGCTGTGCTGACACCAATGA
TGAAACCCTTCATCTACAGGCTGAGGAACAAAGACATGCATGGGGCTCTG
GGAAGATTCCTATACAAACCCTTTAAGAGGCCAATA
The above packets are sent at various times and different networks. The data packet size can be considered as the header and packet number as the trailer of data packet. We consider that two information the total message length and number of packets N (144 and 4 respectively for above example) has been communicated to the receiver through a secure channel. These packets when received on the receiver’s end can be decrypted using the keys (nucleotide sequences used in Clastal W, the crypto transform and the relation ) and following the steps mentioned in the algorithm.
In the proposed algorithm, the data, ready to be sent, is broken into N arbitrary parts. These parts are to be sent through different communication channels at different times. As a consequence, it would be almost impossible for any attacker to get back all those parts. Even if one gets all the parts again it would be difficult for him/her to get the original information by properly merging the parts because key packets have to be recognized properly. In our algorithm a steganographic method is used, the strength of DNA steganographic lies in our conjecture that deciphering on the basis of cryptanalysis techniques like chosen plain text attack, Chosencipher text attack or adaptive chosen-cipher text attack etc become fruitless because it is mathematically infeasible to extract the whole information from these parts in reasonable time.
Authors are grateful to Dr. Sugata Sanyal of TIFR Mumbai and Dr. Rangarajan Athi Vasudevan for his valuable suggestions and visiting students Mr. Rajneesh Singh, Ms. Snigdha Das and for their valuable technical help in making advanced C programs and other computer applications on Windows support used for this study.