To implement such a system would require a huge network of trust. Otherwise it would collapse as malicious individuals manipulated the system. Such a network ne

To implement such a system would require a huge network of trust. Otherwise it would collapse as malicious individuals manipulated the system. Such a network needs a wide reach in order to make it reasonably certain that any given individual will be listed in its database. Possible? Yes. Making it useful? Well, thats up to you. Building the initial database could be quite difficult.