User authentication and file sharing in multichain

Question

I am a newbie in multichain development and I am going through the documentation with multichain-node wrapper for json-rpc api. I have two use cases which I am unable to understand and implement it on multichain. I have following scenarios.

1. User authentication: How can we create user login signup module on multichain such that user can register and login to see and perform different functions on blockchain like file transfer, message transfer etc ?

2. How to send file in such a way that only the recipient can read the contents of that file.

Answer 1

Regarding 1, MultiChain is not like a regular database – anyone running a node directly has full access to the blockchain's contents. So this login/signup module is something you would need to build at the application level, to allow access to a specific node.

Regarding 2, you would use straightforwards encryption for this, and only reveal the key to the recipient. For a detailed tutorial on performing multi-way confidential messaging over a blockchain, please see:

https://www.multichain.com/developers/stream-confidentiality/