*c*= E(3,

*p*) = (

*p*+

*3*) mod (26) where p is the plaintext and c is the cipher result. This is one of the simpler examples that if you knew it were being used then you could attack and recover both the plaintext and ciphertext. We also learned about the extensive and complicated advanced encryption standard. AES creates a thorough course of bit manipulation and transformation from four specific implementations of addRoundKey, subBytes, shiftRows and mixColumns [2]. AES breaks the data into 2 character hexadecimal numbers or 8 digit binary numbers to produce a 4 by 4 matrix. AES involves mathematical operations and resorting of the different matrix cells. The first round involves key expansion which produces numerous keys to be used throughout the rest of the process. Addroundkey is the next process in the first round but the last in every other iteration. Addroundkey process creates a new string of data with a key generated from the expansion method. Then comes the subBytes. In subBytes, the complete matrix is changed. Some research can provide a value to swap using S-box transformation for the values contained in each spot of matrix. ShiftRows follows subBytes and moves each rows to the right by the numbers of indexes of the row it is located in. MixColumns then performs the two mathematic operations of multiplication of the each column element of the encrypted text with the each rows element of a fixed matrix for this procedure. The product of each result is xor to assigned one value to the cell. An illustration of this is provided below [2].

^{n}and c as log

_{2}s [4]. The following is a brief excerpt directly from the article, “for example, if we choose N = 4 and M = 4 i.e. a 4 x 4 x 4 x 4 matrix then S = 4^4 = (2^2)^4 = 2^8, therefore C = 8 bit = 1 byte. If we choose N = 4 and M = 8 i.e. an 8 x 8 x 8 x 8 matrix then S = 8^4 = (2^3)^4 = 2^12, therefore C = 12 bit. If we choose N = 5 and M = 4 i.e. a 4 x 4 x 4 x 4 x 4 matrix then S = 4^5 = (2^2)^5 = 2^10, therefore C = 10 bit” [4]. Once the matrix is created, there is a process of diagonal swapping to reorganize the numbers shown in the image below [4].

[2] Pitchaiah, M., and Philemon Daniel. "Implementation of Advanced Encryption Standard Algorithm." International Journal of Scientific & Engineering Research ISSN 2229-5518 3.3 (2012): 1-6. Web.

[3] Kuppuswamy, Prakash, and Saeed Q. Y. Al-Khalidi. "Hybrid Encryption/decryption Technique Using New Public Key and Symmetric Key Algorithm." MIS Review 13.2 (2014): 1-13. Web.

[4] Tunga, Harinandan. "A New Polybit Shuffling Encryption and Decryption Algorithm Based on N Dimensional Encryption-Decryption Matrix." International Journal of Emerging Technology and Advanced Engineering 2.2 (2012): 143-49. Web.

[5] Srinivararao, P., Lakshimipriya, P. V., Azad, P. C. S., Alekhya, T., Raghavendrarao, K. and Kishore, K. “A Technique for Data Encryption and Decryption.” International Journal of Future Generation Communication and Networking 7.2 (2014) 117-126 Web.

## No comments:

## Post a Comment

Thank you very much for viewing this entry and I hope you are able to return soon to continue to enjoy more of the site.

Please share your thoughts in the comment section.

Be blessed and enjoy life!