To:
scottr@antd.nist.gov (Scott Rose)
Cc:
dnssec@cafax.se
From:
Bill Manning <bmanning@isi.edu>
Date:
Thu, 10 Oct 2002 05:50:29 -0700 (PDT)
In-Reply-To:
<008901c27052$7871d370$b9370681@antd.nist.gov> from Scott Rose at "Oct 10, 2 07:45:02 am"
Sender:
owner-dnssec@cafax.se
Subject:
Re: root zone signing and key lengths/lifetimes
% They recommend a min length of 2048 for RSA keys used by Certificate % Authorities. These keys are usually rolled over every 2 years. Since a % root key signing key will be very rarely used (only sign the root zone key), % it will be used less often than a CA signing key. Any root zone keys could % be rolled over more frequently, and shorter. And that there should be % procedures in place to adapt to new cryptanalysis advances. % % The DNS has a similar "crypto profile" as a certificate scheme (i.e.. known % plaintext, public key, etc). So looking at the key management schemes % sounds reasonable to me, but I'm not a hardcore security guy. % % Scott we are using a key signing key with a validity period of 12 months and zone signing keys of 30 days in the testbed. The key signing key is 4096 bits and the zone keys are 1024 bits. They could be longer (length/duration), but we are still becoming comfortable with the operational logistics. A distinction between CA keys and DNS keys is that with current tools/techniques, there is more "handling" of the DNS keys by operators/users, e.g. they are less embedded in the applications. --bill