DES and 3DES

From: Subba Rao (castellan2004-mail_at_SPAMBUSTER.yahoo.com)
Date: 10/24/04 

Date: Sun, 24 Oct 2004 11:47:53 -0500

Hello everyone,

I have a question about DES and 3DES.

This is what I know so far.

• Initially DES was developed by IBM and used the Lucifier algorithm
(128-bit). It was modified to use 64-bit (56 bit key and 8 bit parity
bit) key and was called Data Encryption Algorithm (DEA).

• 3DES (same as DES) performs 48 rounds (as opposed to 16 rounds of DES)
of encryption.

What is the default DES or 3DES key length? Is it 56 bit or 128 bit?
I am under the impression that 3DES always uses 128 bit encryption.
It is for that reason alone it is more secure. Am I right on that?

Can 3DES encryption be done with smaller key sizes? If yes, is it
part of the best practices?

For encryption/decryption, does 3DES perform 48 rounds on the
data OR use 3 separate 56-bit keys on the data?

Thank you in advance. 

-- 
SR
castellan2004-mail@SPAMBUSTER.yahoo.com
Please remove SPAMBUSTER to reply via email.

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