Subject: Protocol Action: 'Determining Strengths For Public Keys Used For Exchanging Symmetric Keys' to BCP

From: The IESG <[email-masked]>
Date: Tue, 10 Feb 2004 13:33:54 -0500

The IESG has approved the following document:

- 'Determining Strengths For Public Keys Used For Exchanging Symmetric Keys '
   <draft-orman-public-key-lengths-08.txt> as a BCP

This document has been reviewed in the IETF but is not the product of an
IETF Working Group. 

The IESG contact person is Steve Bellovin.

Technical Summary
 
 This document sets out an approximate equivalence between key lengths for 
public key algorithms (i.e., RSA) and symmetric ciphers such as AES.  More 
precisely, it provides guidance on the proper public key modulus size to use
to achieve a comparable level of protection as a given symmetric cipher.
 
Working Group Summary
 
 The recommendations here differ somewhat from NIST's numbers.  However, all
such recommendations are at best approximations to the truth, given that 
they rely on future advances in hardware and algorithm development.  The 
differences are thus not believed to be significant.

Protocol Quality
 
 Steven M. Bellovin reviewed this document for the IESG.