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Hill Cipher
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I am looking for assistance from a cryptologist or anyone knowledgeable with the Hill Cipher. I was trying to solve a problem that given a certain plaintext and ciphertext i have to re-create the encryption matrix. my questions are: 1. Does the encryption matrix only contain integers? because when I am finding they encryption matrix (2x2) i am getting some weird fraction that doesnt seem right. 2. Does the encryption have to be PlainText * Encryption Matrix = CipherText or can it be Encryption Matrix * PlainText = Cipher Matrix? |
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Re: Hill Cipher
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by
on 2011-10-16 03:21:22 (edited 2011-10-16 03:26:51)
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For my unterstanding about cryptography, the encrypted message or words was hidden using codes or symbols corresponding on its equivalent integer form arranged in the manner of mathematical or logistic equations that can be solve or unlocked using logistic or mathematical methods of solving. My Answer in your First Question: I think any symbols, characters, or messages was assign in the forms of number or group of integers. For example, 1 is only character or string, but if you identify it in mathematical way or by its numberical value, it is 1, but you can also assign a different value of 1 if you identify it as a string or character. H is also character or string, but if you identify it in mathematical way, there is many mathematical symbols representing H (H = Height, can be found from the equation in solving for the Area of a Rectangle), but the value is converted depending on the value that it represents. In a encryption, we can assign numbers or integers as a Letter, Symbol, or Character's equivalent so that we can solve those matrixes in a mathematical way using encoded matrixes in a form of numerical values or integer. My Answer in your Second Question: It's up to you. There are many possible ways in making an encryption. But if you use the Hill Cipher method, matrix multiplication was used. Vectored text corresponding to the letters multiplied to a encoded matrix and multipled all to a Modulo (Mod 26 is common) to get the Cipher Text. 3x3 Encoded Matrix was always use, but you can use any size as long as it is a square. Cipher Text = (Plain Text * Encoded Matrix) mod 26 You can use this link... http://www.academypublisher.com/ijrte/vol01/no01/ijrte0101663667.pdf I use it as a reference for my Cryptography Program in my Programming Subject, but there is some mathematical equation that can help you regarding to your problem. I'm not an expert in Cryptography, but I just shared what I've learn. If there is some mistakes in what I said, just correct me and I accept it so I can learn to correct what I've learned. I Hope I just give you the right solution to your problem ... |