Why is PRE method more suitable for N: N communication than PKE method? And is there any further information / links for the use-case to manage a corporate password?
Imagine the following. You are trying to build an e2e encrypted group chat. For security, each message is encrypted with its own symmetric key, and you want to invite people to the chat or revoke access. You'd need to encrypt
every message key for
every participant.
Now imagine you want to grant access to all historical messages to a new participant. You'd need to encrypt a symmetric key for every historical message for him.
So, in brief, you reduce the number of cryptographic operations from `n_participants * n_objects` to just `n_objects`.
Now, imagine that participants would also need to encrypt messages (or files) they publish with everyone's public key. That's also not convenient and not necessarily always safe.
You can also check how e2e encryption / ACLs are currently being implemented in Swarm w/o using proxy re-encryption. They do pretty smart tricks to provide forward secrecy, but still, for every change they require the owner of the data to overwrite `log(N)` encrypted symmetric keys, and the owner of the data cannot trust third parties to write to their dataset.
