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Re: ESP transform with RC5



> From: Bill Sommerfeld <sommerfeld@apollo.hp.com>
> 
>    At 05:36 PM 3/14/96 PST, baldwin wrote:
>    >IPsec members,
>    >        I have just submitted two informational RFCs to the Internet 
>    >Engineering Task Force that specify how the high performance RC5 cipher can
>       
>    >be used to add privacy to packets transmitted over the Internet.  
>    
>    This is the second time in the week that I have heard 'RC5', and have not
>    heard it mentioned before this.
>    
>    I realize that many things happen in the crypto field that I do not see
>    right away, but how recent is the introduction of RC5 to the broader crypto
>    community?
> 
> ~1995 or thereabouts.  This is a *very* new cipher, so it's not
> something I'd actually want to implement or use until it's had a
> lot more shakeout time.
> 

FYI - the algorithm is based on data-dependent rotates.
Not to beat a dead horse, but rotates can take anywhere
from 3-5 operations on a RISC (which typically don't
have rotates), and data-dependent rotates can double that.

Joe
----------------------------------------------------------------------
Joe Touch - touch@isi.edu		    http://www.isi.edu/~touch/
ISI / Project Leader, ATOMIC-2, LSAM       http://www.isi.edu/atomic2/
USC / Research Assistant Prof.                http://www.isi.edu/lsam/