a better Do-Not-Intrude registry

[totojepast]

Using the Bloom Filter instead of the hashes (parts of the hashes to
be precise) would make the registry file smaller and more efffective:
http://en.wikipedia.org/wiki/Bloom_filter

Bloom filter anonymizes the e-mail address better. It has been used
for a distributed public whitelist project:
http://loaf.cantbedone.org/about.htm

[secondwheel]

Size wasn't a real problem with the BlueFrog registry file.
The issue was that spammers can directly attack users whose emails are
in the registry.

The Bloom filter doesn't address the problem, either. If it works as
a registry (and spammers can clean their lists using the registry)
then they can always just compare their lists pre- and post- cleaning
and focus their attacks on the emails that were removed.

You can't get around that flaw if you're going to have a registry at
all.
The only real options are to:
* wait until you have a very large subscriber base before building a
registry (reduces the risk for individuals) or
* not use a registry

~sw