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View Full Version : Solving linear congruences


stunner5000pt
Apr20-04, 07:27 PM
another little bit of help and this is NOT a homework assignment this is for an exam i need to understand it

the qustion is find the decryption function for C = (7M + 9 ) mod 26

how do i fin the decryption function using the inverse?


that is 15 in this case

matt grime
Apr21-04, 05:18 AM
the same way you do it for any other equation:
you've just got to find what the multiplicative inverse of 7 is in U(26)
I don't see where 15 comes from.