
May 16th, 2003, 10:46 PM
#1
Member
modular mathmatics
would using modular math be a good way of making a fast encryption system?

May 16th, 2003, 11:56 PM
#2
What do you mean by "modular maths"?
I'm sorry but I don't really understand your question. Could you develop your thinking please?
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May 17th, 2003, 12:16 AM
#3
Member
by modular math i believe hes talking about the % operator. it returns the remainder given two numbers, ie 10%4 is 2 and 100%10 is 0. as for how it can be used for a fast encryption system, i dont follow him there.

May 17th, 2003, 12:41 AM
#4
I think that creating an encryption system based on remainders would be quite difficult, or even impossible. All depends on what exactly you want to make with them: if you want a not too complicated and fast system, I believe it's impossible. Think how many ways there are to reach a particular remainder and how you could make the difference between those ways during encoding and/or decoding processes.
KC
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May 17th, 2003, 12:42 AM
#5
Modular math as cire defined it is a great function to use for hash tables. It allows for very efficient searches (in O(1) time if done properly). Maybe sectac confused encryption and searching?? or maybe there is a way to use to make good encryption. I'm just rambling now.
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May 17th, 2003, 06:52 AM
#6
Junior Member
To answer your question in one word: Yes.
Modular arithmetic forms the basis for number theory and many cryptosystems. A very simple, old, and well known example is the caesar cipher or shift cipher. Each letter of the alphabet is replaced with an integer from 0 to 25. A caesar cipher is then a function f(n) = (n+m) mod 26 where n is the integer representation of the letter and m is an integer representing the degree of shift. The caeser cipher is a private key cryptosystem, but public key cryptosystems are based on modular arithmetic also, a rather brilliant modern example is RSA. In RSA crypto each character is replaced with an integer and then those numbers are grouped into blocks of 4 digits. A 4 digit block of plaintext M is transformed into the the ciphertext C through the formula C = M^e mod n where n=pq. p and q are prime numbers (huge prime numbers) and e is an integer that is relatively prime to (p1)(q1). Then the cipher text is decrypted with the formula M = C^d mod n where d is an inverse of e mod (p1)(q1).
These are just a couple examples, but if you're really interested you should definitely read:
Handbook of Applied Cryptography by Alfred J. Menezes
Applied Cryptography by Bruce Schneier (aka the crypto bible)
A Course in Number Theory and Cryptography by Neal I. Koblitz
There are lots of other too, but these 3 are classics. The Handbook is fairly mathematically intensive and I don't know how mathematically inclined you are, but its the best crypto book out there IMHO and you can download the whole thing for free at http://www.cacr.math.uwaterloo.ca/hac/

May 17th, 2003, 04:06 PM
#7
I just like XOR Trees and simple algorithm layers based on a key....
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May 18th, 2003, 04:48 AM
#8
Member
i beleived (at least i thought) that PGP used modular mathmatics , you password being translated into your key. But with HUGE numbers. something like, 238977238923999100399983%1229938854 = "watever"
then your pub encryption key is your large first number, and your system uses the 2nd two from your password.... sum such,,,, i gotta read up on it again
sectac
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May 18th, 2003, 05:15 AM
#9
Originally posted here by sectac
i beleived (at least i thought) that PGP used modular mathmatics , you password being translated into your key. But with HUGE numbers. something like, 238977238923999100399983%1229938854 = "watever"
then your pub encryption key is your large first number, and your system uses the 2nd two from your password.... sum such,,,, i gotta read up on it again
well if you knew PGP used modular mathematics, why did you have to ask if it would be good for encryption?

May 19th, 2003, 08:40 PM
#10
Member
because i was not sure if it was true or not, wondering if anyone can confirm or add any input to a new system im creating using modular mathmatics along with arrays
ttyl
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