Hyperledger - How can I use transaction certificates to enforce privacy

Question

I am creating an app that performs a bidding process for antique furniture company.

My requirements are that suppliers shouldn't be allowed to see other suppliers' bid.

Only the manufacturer and the bidding supplier should be able to see the transaction in a the block, so only the both of them know who won the bid.

I have looked this up, and I think the transaction certificates will address my privacy concern.

I am able to request for multiple transaction certificates using REST API. However, I don't know how to utilize them.

Is it meant to be used outside chaincode or as a parameter to a chaincode function.

I am currently using v0.6 of the Hyperledger fabric for my chaincode. For my front end, I'm using Node.JS HFC SDK v0.6.5.

Answer 1

The transaction certificates don't actually address privacy matters. rather, they authenticate that the transaction comes from a valid node.

These certificates invoke transaction in the chaincode.

I suggest you to start using the v1.0 of the Hyperledger Fabric coz v0.6  can't scale very well and can't support true private transactions and confidential contracts.

The v1.0 allows you to isolate Blockchain  inside your network. That's possible through the channels, that when defined,let you define who are the members of it, so, only those peers could send transactions through that channel. Therefore, only members of the channel could see your transactions.

So, for your use case, you should create four channels, each one for each supplier, and the manufacturing company should be a member of all channels.