[46391] in Cypherpunks
Re: 2047 bit keys in PGP
daemon@ATHENA.MIT.EDU (Sten Drescher)
Wed Jan 3 16:07:03 1996
To: Laszlo Vecsey <master@internexus.net>
Cc: "Douglas F. Elznic" <delznic@storm.net>, cypherpunks@toad.com
Reply-To: Sten Drescher <dreschs@austnsc.tandem.com>
From: Sten Drescher <stend@cris.com>
Date: 03 Jan 1996 14:38:51 -0600
In-Reply-To: Laszlo Vecsey's message of Wed, 3 Jan 1996 13:35:50 -0500 (EST)
This message is in PGP/MIME format, according to the Internet Draft
draft-elkins-pem-pgp-02.txt. For more information, see:
http://www.c2.org/~raph/pgpmime.html
(Actually, trailing whitespace is not treated specially,
so it is a proposal likely to be adopted in the 03 draft.)
--0W1jC0x37oO9a6
Content-Transfer-Encoding: quoted-printable
(sorry if this is a duplicate)
Laszlo Vecsey <master@internexus.net> said:
LV> Are you sure it's a bug in the DOS version? When I did a pgp -kg in
LV> my UNIX shell (US version 2.6.2) I also entered 2048 bits and it too
LV> created a 2047 bit key instead.
=09I had heard elsewhere that there was such a bug. My mistake,
then.
LV> Why is there a limit to the size of the key anyway? It's too bad PGP
LV> doesn't support any size key (within reason).
=09As I understand it (which, given my previous error, is in
serious doubt), after a point the IDEA session keys become far easier to
use a brute force attack on than the RSA keypair. Since I think that
increasing the RSA keysize is supposed to double the attack time, if a
RSA key size of N takes as much time to break as 1 IDEA key, making the
RSA key N+8 bits makes it better to break the IDEA keys of 200 messages
rather than the RSA key.
=09Does anyone know if there are comparisons of estimates of the
time to break the IDEA session keys used in PGP vs time to break RSA
keys of various sizes?
--=20
#include <disclaimer.h>=09=09=09=09/* Sten Drescher */
To get my PGP public key, send me email with your public key and
=09Subject: PGP key exchange
Key fingerprint =3D 90 5F 1D FD A6 7C 84 5E A9 D3 90 16 B2 44 C4 F3
Junk email is NOT appreciated. If I want to buy something, I'll find
you.
--0W1jC0x37oO9a6
Content-Type: application/pgp-signature
-----BEGIN PGP MESSAGE-----
Version: 2.6.2
iQCVAwUBMOrpYlvBgRcdkGwFAQH/oAQAsry7Ov62G93GZBPE7gxnIL7V0YyLpo1Z
nfNWhliHzU2S8yQ04SCZV2ttQmB9VcDQ8aG9es0FKy5YCjeMFqvq6Cfu9T+WFE04
OTPGgHvUDtIYzooSslr5lWSa+KlIMFluxUf6fI7Loey8kvmMcTPzTcL7sMNKE4LI
sJ/mtJqQAfo=
=1vZE
-----END PGP MESSAGE-----
--0W1jC0x37oO9a6--
