Re: [Newbie] Prime factorization question

From: Bill Unruh (unruh_at_string.physics.ubc.ca)
Date: 10/08/03 

Date: Wed, 8 Oct 2003 10:22:38 +0000 (UTC)

tomstdenis@yahoo.com (Tom St Denis) writes:

]"Lorenzo Bolognini" <lorenzo@mysurname.net> wrote in message news:<Bkzgb.179955$hE5.6064550@news1.tin.it>...
]> "Bill Unruh" <unruh@string.physics.ubc.ca> ha scritto nel messaggio
]> news:bluef3$md2$1@string.physics.ubc.ca...
]>
]> > Yes, the primes are randomly selected from those with a certain length.
]>
]> So they are known and sure they are prooven and certificated primes
]> (otherwise the cipher would be vulnerable to other attacks than plain
]> bruteforcing) and they are finite so the number of possible primes that may
]> generate the cipher is very much restricted... well how many are they? Not
]> that I want to procastinate my thought that you said to be mistaken but I
]> just want to understand this stuff something more. (Ok so maybe starting
]> studying number theory would be fine u one could say! ;-)

]Amateurs....

Yes, but you are an amaeur reader. What was being talked about was RSA,
not Diffie Hellman. The OP was under the impression that RSA used a set
of known, programmed in primes to create the product. It does not. Just
as DH does not use a known exponent.

]What you're thinking of is Diffie-Hellman could [and should] use known
]primes. Diffie-Hellman is not based on factorization but discrete
]logarithm for security. The two problems are related but the latter
]is somewhat harder [in practice] to attack than the former.

]Tom

Relevant Pages

  • Re: fooling primality tests
    ... Tom St Denis wrote: ... are needed "only" the primes from 2 to ... [goto the zetagrid ...
    (sci.crypt)
  • Re: Enigma 1633 - Same perfect square
    ... Harry, Tom and I were each looking to find ... difference was also the product of two primes, ... was the same perfect square. ...
    (rec.puzzles)
  • Re: Some Prime number questions
    ... but maybe someone at the NSA could help ... To be very clear the number of primes less than x approaches x/lnas ... Tom previously posted which should be no surprise. ...
    (sci.crypt)
  • Re: DR Reductions
    ... Tom St Denis wrote: ... For primes of certain types of special forms, ...
    (sci.crypt)
  • Re: Weak keys for RSA ?
    ... Robert D. Silverman RSA Public Key Validation, ... that p,q are so-called strong primes. ... outline how to guard against the Bach/Shallit ... a standard. ...
    (sci.crypt)