It’s very frequent that some content must be private. This spans from instant messengers to sharing a document with collaborators.
In the case of 1:1 content sharing, normally sender would encrypt with receivers public key and only receiver would be able to decrypt.
In NEAR, each account can have many keys. Also if keys are stored on hardware device or in some other form of custody - it would be extremely hard for receiver to actually decrypt.
There has been a proposal described in Stackoverlow answer: https://stackoverflow.com/a/62291714
There are few more advanced tools like proxy re-encryption that exist as well, which may allow to simplify the interaction flow in expense for more cryptography and computation off chain.
Curious to discuss the proposal and if there are alternatives here. Ideally we should formalize something to the form of implementable milestones.