Decryption algorithm: reverse the encryption algorithm

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Reference no: EM13304389

Program a secret key encryption and decryption method using c programming language based on the following:
- Your program must take an array of 8 characters as an input and output an array of 8 encrypted characters.
- Write the code necessary to create 8 unique random substitution tables, one for each character of the array.
- Your methods must use a 64-bit key (can be represented as another array of 8 characters) derived from an 8-character password.
- Encryption algorithm: Take the input array and xor it with the key. Using the xored output, perform a character-by-character substitution using the different substitution tables. Perform the permutation step once after the substitution step. For the permutation step, (circular) shift the bit pattern by one to the left with the leftmost bit becoming the rightmost bit. Repeat the above steps 16 times, corresponding to 16 rounds, with the output of a round serving as the input for the next round.
- Decryption algorithm: Reverse the encryption algorithm. The permutation, however, should (circular) shift the bit pattern by 1 bit to the right.

Reference no: EM13304389

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