[141] in cryptography@c2.net mail archive
Re: PCS Encryption?
daemon@ATHENA.MIT.EDU (Adam Back)
Mon Feb 3 22:43:15 1997
Date: Mon, 3 Feb 1997 23:59:48 GMT
From: Adam Back <aba@dcs.ex.ac.uk>
To: meredith@ecid.cig.mot.com
CC: ggr@Qualcomm.com, cryptography@c2.net
In-reply-to: <32F62742.7F34@ecid.cig.mot.com> (message from Andrew Meredith on
Mon, 03 Feb 1997 17:58:26 +0000)
Andrew Meredith <meredith@ecid.cig.mot.com> wrote:
> Greg Rose wrote:
> [...]
> > The conclusion is that neither way of doing it is truly
> > cryptographically strong, but both are a lot better than
> > listening to Princess Di call Newt "Squidgy" on a Radio Shack
> > scanner.
>
> GSM uses the A5 algorithm which *is* cryptographically strong, but is
> unfortunately considered to be top secret stuff. If, however, you were
> to pick up a copy of "Applied Cryptography, 2nd Edition" by Bruce
> Schneier you may find something of interest.
A5 has a 40 bit key space (not strong, though perhaps you were
referring to the design and not the woefully inadequate key length).
I presume the ref. to App. Crypto refers to the source code for A5 in
the appendix.
Adam
--
print pack"C*",split/\D+/,`echo "16iII*o\U@{$/=$z;[(pop,pop,unpack"H*",<>
)]}\EsMsKsN0[lN*1lK[d2%Sa2/d0<X+d*lMLa^*lN%0]dsXx++lMlN/dsM0<J]dsJxp"|dc`
