Re: 3-DES and SHA-1-HMAC
From: Walter Roberson (roberson_at_ibd.nrc-cnrc.gc.ca)
Date: 10/23/03
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Date: 23 Oct 2003 16:27:05 GMT
In article <f01ba7b8.0310230226.7869b885@posting.google.com>,
Marco <tozzio@hotmail.com> wrote:
:I read that 3 DES somethimes use 112 effective bits and somethimes 168
:effective bits. SECURE SERVER policy how many bits use?
There is a known attack against 3DES. If you had a LOT of memory,
then you could effectively do the middle DES encryption stage as a
single lookup. This reduces the theoretical effectiveness of 3DES
to no more than 112 bits.
In practice, no-one has that much memory (at least not and
admits it!) -- it would take something like 10 petabytes
(or possibly 7 times that much; I'm not sure.)
See also
http://www.acmet.com/html/3des.html
http://www.vpnc.org/ietf-ipsec/92.ipsec/msg02277.html
http://www.vpnc.org/ietf-ipsec/92.ipsec/msg02278.html
http://www.vpnc.org/ietf-ipsec/92.ipsec/msg02285.html
-- Perposterous!! Where would all the calculators go?!
- Previous message: John Smith: "Re: NetScreen 5XT and VPN connection"
- In reply to: Marco: "3-DES and SHA-1-HMAC"
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