Ask High Scalability: How to build anonymous blockchain communication?

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I am building a 2 way subscription model I am working on a blockchain project where in I have to built a information/data portal where in I will have 2 types of users data providers and data recievers such that there should be anonimity between both of these.

Please guide me how can I leverage blockchain (I think Etherium would be useful in this context but not sure) so that data providers of my system can send messages to data receivers anonymously and vice versa data receivers can request for data through my system to data providers.

I believe, it work if we can create a system where in if a user has data, it will send description to the server, The system will host this description about data without giving the data provider details.

Simultaneously server will store info which user has the data. When data receiver user logs in to system and wants and sees the description of data and wants to analyze that data, it will send request to server for that data. This request is stored in the server and it will allow access to data without receiver knowing who wants to access that data, but it will trigger a message to receiver that an anonymous user wants to access data and would data.

Can you please guide me how to build architecture of this system and how to proceed to do a POC?