[p2detar]

That's not how it should work though. The post should get encrypted only once with a symmetric key i.e. AES, and then this gets encrypted with each of the followers' public keys. So it's not the post itself but the encryption key that must be scaled. This is how PGP-encrypted E-mail works.

[Raed667]

you’re still encrypting n-times, the post needs to be stored n-times and that’s even before thinking about key rotation and server portability

this is not practical