Can you explain some mechanisms of privacy in Hyperledger Fabric v1.0 - those already implemented and those planned to be implemented in the future?
I understand channels are like seperate blockchains. I also went through the document on https://jira.hyperledger.org/browse/FAB-1151, where I have found two more mechanisms: one is private data, and other is encryption. Can you explain what would be the beast approach to use in the following scenario.
Each car needs car insurance. Let's say the owner of the car wants to change his insurance company. He signs the contract with new insurance company. Let's say there is also a regulator. The new insurance company informs the regulator about the new contract. The regulator then informs the old insurance company that the car is no longer insured there, but does not inform them about the name of the new insurance company. So we have assets that are shared in the network, but also some private data which only some participants can see. I am guessing this is one chain, so the use of multiple channels makes no sense here.
I do not completely grasp the concept of private data. Is that data supposed to be private only for one peer / company, or can it be shared between multiple companies, but not all of them? Is this the way to go in the scenario? What would be different reasons / use cases to use encryption vs. private data? What mechanism should be used in the described scenario?
First of all, these two concepts of encryption and private data are not mutual exclusive, the intent is to being able to use them both.
The concept behind having private data is to keep certain data keys out, to prevent them to being sent to the orderering service and to distribute them separately across the peers via gossip.
Now, the encryption needed to divide private data into portions which will be encrypted according to the visibility rules, e.g. to allow to read and see the relevant portions of the data to only involved parties.
With all that said, please note that FAB-1151 is still under development/design process and to be added post v1.0 of Hyperledger Fabrics.
来源：https://stackoverflow.com/questions/44616531/privacy-on-hyperledger-fabric-v1-0