🚀 go-pugleaf

strnlght@netcom.com (David Sternlight) writes:

    bs@gauss.mitre.org (Robert D. Silverman) writes:

        gilgalad@quip.eecs.umich.edu (Ralph Seguin) writes:

            27392450308603031423410234291674686281194364367580914627947367941608692026226993634332118404582438634929548737283992369758487974306317730580753883429460344956410077034761330476016739454649828385541500213920807

            Can you factor this number [in your lifetime]?  If so, you may be

        What is the source for this number? Is it a random integer? Is it
        an RSA number, constructed as the product of nearly equal primes?
        If the latter it is out of current computational range.

    (Correcting a previous post)
    Couldn't you take the approximate square root of the number, truncate the
    result, and then start searching up and down from there if the number is the
    product of two nearly equal primes?

Yes you could, of course.  Note however, that the number has 209 digits.
Now suppose that it has two prime factors of with 100 digits and 109
digits.  Then you would search quite a while.  Bob probably meant that it
must not be the product of two primes of nearly equal *size*.  Especially
it must not have a prime factor with less than 40 digits, otherwise it
would be possible to attact it with the elliptic curve method.

Martin.

-- .- .-. - .. -.  .-.. --- ...- . ...  .- -. -. .. -.- .-
Martin Sch"onert,   Martin.Schoenert@Math.RWTH-Aachen.DE,  +49 241 804551
Lehrstuhl D f"ur Mathematik, Templergraben 64, RWTH, D 51 Aachen, Germany