Bin Chen wrote: > Hi, > > Many cryptography algorithm used prime to do the modular math, but I > don't know why it need to use prime but not many ordinary numbers? > > Thanks > Bin
I would guess it is because the integers modulo any prime are a "field", whereas the integers modulo a non-prime are mearly a "ring". More concretely, for any integer i and any prime p, there is guaranteed to be an integer j such that i * j == 1 mod p. This is not guaranteed when the modulus is not a prime. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/algogeeks -~----------~----~----~----~------~----~------~--~---
