Distinguish pq Prime Cases: Algorithm for ppt

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The discussion revolves around distinguishing two cases of prime pairs (p, q) based on their congruences modulo 4. Participants inquire about the existence of a polynomial-time algorithm (ppt) that can differentiate between these cases. The conversation touches on the properties of prime numbers, particularly regarding their divisibility by 3, noting that only the prime number 3 fits this criterion. There is a consensus that there are infinitely many primes congruent to 1 modulo 3, although proving it remains elusive. The complexity of the problem suggests potential applications in cryptography, particularly in creating simple bit-commitment schemes.
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Given pq where p < q are prime, but either (p \equiv 1 \mod 4 and q \equiv 3 \mod 4) or (p \equiv 3 \mod 4 and q \equiv 1 \mod 4).

Is there a ppt algorithm that will distinguish the two possibilities?
 
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How many primes are \equiv 1 \mod 3
 
More importantly, for how many primes q is it true that q is divisible by 3?
 
pasmith said:
More importantly, for how many primes q is it true that q is divisible by 3?

At least there's one of those!
 
pasmith said:
More importantly, for how many primes q is it true that q is divisible by 3?

The definition of prime says a prime is divisible only by itself and 1, hence only 3 fits for the occasion :P
 
You people must be some kind of super geniuses.
 
Dragonfall said:
Given pq where p < q are prime, but either (p \equiv 1 \mod 4 and q \equiv 3 \mod 4) or (p \equiv 3 \mod 4 and q \equiv 1 \mod 4).

Is there a ppt algorithm that will distinguish the two possibilities?

I'm not familiar with one, but I'm not too familiar with these sorts of things. Is this a cryptography problem? I thought that factoring primes was always more than polynomial time.

PeroK said:
How many primes are \equiv 1 \mod 3

Infinite? I can't prove it. But why?
 
There are indeed infinitely many primes that are 1 mod 3. But that's not relevant.

If this problem is hard then it would make a very simple bit-commitment scheme.
 
PeroK said:
How many primes are \equiv 1 \mod 3

pasmith said:
More importantly, for how many primes q is it true that q is divisible by 3?

I should clarify, for the benefit of future readers, that these were in response to the unedited original post which read

Dragonfall said:
Given pq where p < q are prime, but either (p \equiv 1 \mod 3 and q \equiv 3 \mod 3) or (p \equiv 3 \mod 3 and q \equiv 1 \mod 3).

Is there a ppt algorithm that will distinguish the two possibilities?
 
  • #10
Ahh, I was quite confused.
 
  • #11
Somebody clean up all the useless replies here please.
 
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