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Re: Incorporation of AES into IPSec
Tero: No, 3DES do NOT have 168 bits of strength.
Tero: Its effective strength is 112 bits, if you
Tero: have 2^56 blocks of memory. You can find more
Tero: information in the Applied Cryptography
Tero: (Bruce Schneier, ISBN 0-471-11709-9) ) in
Tero: section 15.2.
triple des can support two key sizes--two key or three key. 2key triple
des=112-bits of symmetric strength, 3key triple des=168-bits.
cheers - john
Tero Kivinen <kivinen@ssh.fi> on 06.12.1999 10:48:05
To: jerome@psti.com
cc: Mark Shuttleworth <marks@thawte.com>, ipsec@lists.tislabs.com (bcc: John
Harleman/Certicom)
Subject: Re: Incorporation of AES into IPSec
jerome@psti.com writes:
> > If you were wanting to protect
> > data for 50 years, would 3DES be good enough?
> it's hard to do prediction over so long time, but 3DES has a 168bits key.
> it is safe against a brute force attack. A cryptanalitic breakthrough
No, 3DES do NOT have 168 bits of strength. Its effective strength is
112 bits, if you have 2^56 blocks of memory. You can find more
information in the Applied Cryptography (Bruce Schneier, ISBN
0-471-11709-9) ) in section 15.2. There is also reference there to the
following article:
R.C. Merkle and M. Hellman, "On the Security of Multiple Encryption,"
Communications of the ACM, v.24, n. 7, 1981, pp. 465-467.
which propably contains even more information...
--
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