Are you referring to my DNSSEC remark? You'll want to look at their NXDOMAIN alternative, which says "there are no domains with hashes between 0xCAFEBABE and 0xDEADBEEF", where the 0x... stuff are hashes.
Note that running through a dictionary and looking for hashes "near" the domain you're interested in works if the DNS server is nice enough to hand out responses of the above form; unfortunately, this can also be used to find which host names are valid for a domain (host names aren't exactly crypto-strength passwords). At least djb advocates giving out answers of the form "there are no domains with hashes between 0xCAFEBABE and 0xCAFEBAC0" (that is, exactly bracketing the query), in which case you'd need to do something more clever.
Unfortunately, I'm not intimately familiar with DNSSEC. I'd be happy to learn the answer, though; if you find it, could you post it as a response, or, if takes a while, e-mail me? (E-mail in profile.)
[EDIT: improved wording, make it clear that actually sending the whole dictionary to the DNS server is not necessary.]
Note that running through a dictionary and looking for hashes "near" the domain you're interested in works if the DNS server is nice enough to hand out responses of the above form; unfortunately, this can also be used to find which host names are valid for a domain (host names aren't exactly crypto-strength passwords). At least djb advocates giving out answers of the form "there are no domains with hashes between 0xCAFEBABE and 0xCAFEBAC0" (that is, exactly bracketing the query), in which case you'd need to do something more clever.
Unfortunately, I'm not intimately familiar with DNSSEC. I'd be happy to learn the answer, though; if you find it, could you post it as a response, or, if takes a while, e-mail me? (E-mail in profile.)
[EDIT: improved wording, make it clear that actually sending the whole dictionary to the DNS server is not necessary.]