Ivan Ch <acizlan@...>
I apologize for restarting this old topic, someone sent me a private message so I think the least I can do is to make the problem clear
On Wed, Dec 11, 2019 at 06:51 PM, Gari Singh wrote:
1) hashes on chain cannot be validated by any third party, so they can be used by adversaries to trick honest participantsThe problem is that all the checks you mentioned above are checking something non-verifiable and therefore cannot be used to validate any business logic at all!!! because the actual data is unknown to verifiers/endorsers (who cares about endorsement policy if the endorser doesn't know whatever the heck he is endorsing. block, MVCC, and even transaction sender identity checks got nothing to do with the actual business logic).
of course if the data is in clear text than it would work, because then the endorsers would run the logic inside the chaincode to verify the business logic associated with the transactions being endorsed. Quorum has a host of problems but at least they are exploring crypto/ZKP options like the PoC they did with JPMorgan (to be fair, that was only a PoC, but at least it was a good attempt that fabric's been lacking).
the bottom line is Private data feature does not solve the data privacy problem (or any problem to be honest) but it is given a name and making people believe it does. this is unfortunate because fabric's endorsement architecture is actually a much better platform than anything ethereum to run ZKP cryptos.