Recent content by Chu

Hello all, here is a problem I am working on that is giving me some problems. p,q, and N are defined as in RSA i.e. {p,q} in (Z_p,*), N = pq a in (Z_n,*) g in (Z_{N^2}) s.t. g=aN+1 mod N^2 The problem is to show that the discrete log problem base g is easy in Z_{N^2}, i.e. : given...

Sorry, I'll rephrase. I know a solution must exist from the choices of p,b,and a (this is part of a crypto algorithm where they know x, I do not, and I am wondering if I have sufficent info to solve for it).

Say you are given a=x^b mod p, where p, a, and b are known. Is there a way to solve this? I am pretty sure there is . . . but it is driving me nuts. -Chu

Hello all. I know there is a stupidly easy algorithm to find the prime decompision of a number (i.e. 2*2*2*3*5 is the p.d. of 120) but I can't for the life of me remember it. I need to do this operation on incredibly large numbers (~500 digits) so the naieve way of just starting at 2 and...

After doing some looking I sort of found the way to do this (i.e. reduce it to a much simpler problem). If g is a gerator for a system modulo P, then all p in P can be represented as g^n. For example, in Z_7, the powers of 2 are: 2, 4, 8=1, 2 i.e. we have a cyclic group of order 3 so 2...

Hello all, I am currently writing a program where I need to find a generator in VERY large modular prime systems, where p can be anywhere up to 2^1024. Is there an efficent (i.e. hopefully polynomial time on the number of bits) way to do this? For example, the current system I am working in is...

Hello all, I have a problem with a question reguarding attacking DES. If you don't know how DES (the encryption system) works but know algebra you can still help ;) Essentially -- Part A of the problem (the 'hard' part based on point values) was to prove the complement rule of DES, mainly...

And this is why we don't do math after 20 hours of no sleep :blushing: Just realized how (b) follows from (a).

Frustrating step in a proof -- basic abstract algebra Hello all, I am trying to work on a proof related to information theory, and I have gotten stuck. I am nearly 100% this is true, but it might not be . . . and I am having trouble coming up with a proo for it in any case! ---------- M...