RE: SHA 1 vs. SHA 256 for Root CA

["Ogle Ron" <ron.ogle@xxxxxxxxxxx>]

What size are you planning for your CA keys ?  If you are going to use
RSA 1024, then SHA1 is probably ok.  Also, look at the applications that
you will be using especially for the near future.  They may not work
correctly with anything other than SHA1.  Later on, you could always
re-issue your CA certs with the same keys but with the newer SHA 256
algorithm.

IMHO, go for the ease of use and interoperability than trying to ensure
that everything is extremely secure/unbreakable.

Ron Ogle

-----Original Message-----
From: owner-ietf-pkix@xxxxxxxxxxxx [mailto:owner-ietf-pkix@xxxxxxxxxxxx]
On Behalf Of ROGER YOUNGLOVE
Sent: Monday, January 29, 2007 9:39 AM
To: ietf-pkix@xxxxxxx
Subject: SHA 1 vs. SHA 256 for Root CA


We are standing up a number of CAs (Selfsigned Root, Policy and
Issueing).
The question has come up with the Microsoft CA product we have the
ability 
to chose SHA 1, SHA 256, SHA 512. i believe that SHA1 is not sufficent
for a 
20 year root CA lifespan. I need expert support for moving to SHA 256 at
a 
minimum.

Roger Younglove
Principal Consultant
Ford Motor Company