Answer:
1. What is the XOR cipher for the cipher bitstream of (with a repeated key of 'a' - 0x61 or 0110 0001b): 00000010 00001110 00010100 00000010 00001001
Additional information:
The bitwise operation we use is Z=A XOR B: A B Z ----- 0 0 0 0 1 1 1 0 1 1 1 0 If we use an 'a' (0110 0001) and plain text of "shape" we get: 's' 'h' 'a' 'p' 'e' Input: 01110011 01101000 01100001 01110000 01100101 Key: 01100001 01100001 01100001 01100001 01100001 --------------------------------------------------- Cipher 00010010 00001001 00000000 00010001 00000100 If we use an 'a' (0110 0001) again we get: Input: 00010010 00001001 00000000 00010001 00000100 Key: 01100001 01100001 01100001 01100001 01100001 --------------------------------------------------- Decoded 01110011 01101000 01100001 01110000 01100101 's' 'h' 'a' 'p' 'e'
Ans: couch