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The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:18:26
Jim Gillogly (jim@acm.org)
Fri, 05 Feb 1999 14:20:50 -0800
Somebody wrote:
>> Could you explain in more detail how you use this construct to take the
>> public keys out of the picture?
> It was intended to do exactly what chaffing and winnowing does -- provide
> strong, exportable confidentiality from a shared secret -- not to do RSA
> encryption without symmetric keys. Both parties use their shared secret to
> deterministically generate a 512-bit RSA key, and they use this key to encrypt
> the first bits of a message which has already passed through an a|n transform.
> If rigged properly, no clue is provided as to what the modulus is, and BXA-OK
> RSA acts like a strong symmetric cipher, not a weak asymmetric one.
While this looks like good clean fun, the catch will likely come
during the famous "one-time review" at BXA, wherein they defenestrate
the written regulations and decide whether you've given them enough
information to break the system with no more effort than it would
take them to break DES. If their answer's "no", then your export
application is rejected. I predict it doesn't matter whether
you're using an RSA key that's the same length as the RSA key the
regs say is OK, if it doesn't let them break the traffic. Since
the system does do encryption, they claim you need to have it reviewed.
The advantage of chaffing and winnowing is that it doesn't require
an application to BXA and a review, since it uses only authentication
algorithms. Or at least that's the claim... whether BXA would agree
they have no jurisdiction over it isn't my call.
-- Jim Gillogly Trewesday, 15 Solmath S.R. 1999, 22:11 12.19.5.16.10, 4 Oc 3 Pax, Sixth Lord of Night
The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:18:26