From: gtoal@an-teallach.com (Graham Toal)
Date: Wed, 18 May 94 10:38:21 PDT
To: cypherpunks@toad.com
Subject: Re: PGP 2.5: Mini-review
Message-ID: <199405181736.SAA04822@an-teallach.com>
MIME-Version: 1.0
Content-Type: text/plain


: From: Schirado <schirado@lab.cc.wmich.edu>

: >Printed keyIDs have been incresed to 32 bits, as there were enough keys
: >out there that 24-bit keyIDs were no longer sufficiently unique.  The
: >previous 24-bit keyID is the LAST 6 digits of an 8-digit 32-bit keyID.
: >For example, what was printed as A966DD now appears as C7A966DD.

: So even though the keyservers only have 5,000 or so registered users,
: there are enough people out there using PGP and NOT registering their
: keys with the servers that this extra bit of coding was necessary? Hmm.
: 24 bits gives us 16,777,216 unique ID's. 32 bits gives us 4,294,967,296.
: Are there really over 17 million PGP'ers out there, or is my math-impaired
: brain missing something painfully obvious?

It's the old "birthday paradox" game.  If you're generating numbers at
random within a certain range, how many numbers do you have to generate
before you have a probability >= 0.5 of generating two the same?

Do it first for range = 0..2^24-1 and then for range = 0..2^32-1 ...

G