> Even with that aside, though, most websites nowadays already run to some extent on untrusted hardware (thanks to JavaScript), thus warranting measures to handle untrustworthy IPC.
From a security perspective it is a very bad idea to rely on untrusted data (i.e. that only passed "client validation", but is not validated again on the server). In other words: If the client tampers with some of its data, only it itself should be affected from any problems that this causes.
Agreed, hence the clause "thus warranting measures to handle untrustworthy IPC".
So the question here would be one of replacing server-side verification of untrusted data with peer-to-peer distributed verification of untrusted data.
From a security perspective it is a very bad idea to rely on untrusted data (i.e. that only passed "client validation", but is not validated again on the server). In other words: If the client tampers with some of its data, only it itself should be affected from any problems that this causes.