>>Are there any freely-available secret-sharing packages around? Specifically,
>>I need to be able to set up modestly complex policies to protect a sensitive
>>signature key.
>
> I use Hal Finney's "secsplit". Google found it in a couple of places; it
> doesn't seem to have been updated since 1993.
This is why I don't recommend secret-sharing for important DNSSEC
private keys. Using infrequently maintained software increases the
risk of losing the key, perhaps years from now when you suddenly
decide you need it.
What I ended up designing was to have a meta-root key whose private
key is used to sign perhaps ten "root keys". Keep these root keys
under high security, and dole them out one per year, or whenever you
need to due to a breach. Keep the meta-root private key under very
very high security (my recommendation was to embed it in the
structural members of a skyscraper, such that anyone who tried to get
it -- the legitimate owner or anyone else -- would have to make a lot
of noise for an extended period, in a very public place). I'd put
it as ink on good paper inside steel, rather than rely on some obscure
secret sharing software from ten years earlier, that won't run on
modern bloodstream-resident computers.
Perhaps PGP is well enough maintained, though I wonder how many people
are actually exercising the split-key feature, and whether it can be
used to keep the kind of key that Steve wants to keep. Paper is rather
marvelously flexible at things like that.
John
