I am working for a big consulting firm and we have a platform that exchanges data with couple of big companies. We are trying to enhance then platform on which enterprises will be able to deposit data. The workflow that we are building is that we would like the companies to upload data on the platform, without us knowing who uploaded the data (the reason why: we do not need to every-time sign a complicated NDA).
I had a look at couple of cryptographic systems, I thought of Asymmetric Encryption, but then you need to know the owner's public key in order to decrypt the message.
I also thought of Zero Knowledge Proof, but then again you need to know the identity of the data'owner.
I thought even at merkle tree in order to whitelist specific public key that can access the platform, but then again you need to know the public key's owner.
So any idea, how I can give access to specific users to a platform, without knowing who after that accesses it? Thanks for your help, am a bit stuck.