Proving I'm not Bob.

[s1113645 at tesla.cc.uottawa.ca]

I had an idea for an advertising based net-payment scheme that has 
a particular security flaw making it totally untrustworthy unless it is
possible to prove that you are not a particular person (the publisher 
receiving the ad money) when consuming (viewing or otherwise) the ads.

All its other flaws seem to based on the same sort of identity denial 
problem. Damn!

Any protocols, cryptographic or otherwise?

TIA