Members of Parliament Problem

[ph@netcom.com (Peter Hendrickson)]

I read awhile ago that certain members of Parliament do not speak
their mind regarding the situation in Northern Ireland.  The reason
they give is that they have children and they fear the IRA.

There are times when one wishes to speak anonymously, yet speak
as a member of a group.

Is there a way to take published public keys and combine them with
your own in such a way that your identity is not compromised, but
it is clear beyond a doubt that you control one of a set of public
keys?

Peter Hendrickson
ph@netcom.com