1994-06-17 - Re: Prime magnitude and keys…a ?

Header Data

From: Jim choate <ravage@bga.com>
To: m5@vail.tivoli.com (Mike McNally)
Message Hash: a50813532bdfd720b025766c870760444748bc45bbab2efc017dcf5c553ca022
Message ID: <199406172325.SAA22491@zoom.bga.com>
Reply To: <9406171918.AA05970@vail.tivoli.com>
UTC Datetime: 1994-06-17 23:25:15 UTC
Raw Date: Fri, 17 Jun 94 16:25:15 PDT

Raw message

From: Jim choate <ravage@bga.com>
Date: Fri, 17 Jun 94 16:25:15 PDT
To: m5@vail.tivoli.com (Mike McNally)
Subject: Re: Prime magnitude and keys...a ?
In-Reply-To: <9406171918.AA05970@vail.tivoli.com>
Message-ID: <199406172325.SAA22491@zoom.bga.com>
MIME-Version: 1.0
Content-Type: text

> If you can get the sign of the difference between RSA(your number) and
> RSA(unknown key), then you can discover (unknown key) in log n time.
> That implies, due to the nature of RSA, that you can factor in log n
> time using whatever algorithm it is that makes the determination of
> the sign of the difference. 

No, again   it will allow you to find the secret key, it will not 
provide any information about the factors of that number. It might
be used for that but as you have pointed out, it takes a long time.

If I can take a cypher-text and look at the periodicity of the mod
function when several false keys are provided  I can narrow down
the guess through a binary search. I am going up, not down (ie finding
the factors which must be smaller than n). I am looking for n, not
its *@$^%# factors.

You are asking the wrong question. I am asking, since I can't factor the
keys is there some periodicity in the mod function that I can attack.