Subject: Re: NFS file handles are guessable.
To: der Mouse <>
From: Perry E. Metzger <>
List: tech-security
Date: 03/31/1997 22:47:44
der Mouse writes:
> >>> Will this be "exportable"?
> >> There does not appear to be any text in the current crypto
> >> regulations which specifically control the export of random number
> >> generators.
> Question: what's the difference between a stream cipher and a
> cryptographic-strength random number generator?
> Answer: not much.


A stream cipher can be keyed. If you can't key it, it can't be used as
a stream cipher, because no one can decrypt what gets encoded with
it. Taking away the ability to key it (and keying it off of a
/dev/random) will probably render it exportable.

It is true that a smart person can always re-write the section to do
keying, but then again, a smart person can get a copy of Applied
Cryptography and just type in the functioning version from the book
without having to extensively hack on ours to make it work.