Best cross-platform compression-encryption utility

[DominikHoffmann]

I am looking for a utility that can compress and encrypt a folder hierarchy. It should ideally have these feature:

1. Be cross-platform; versions for at least macOS and Windows should exist. iOS, Android and Linux would be nice, but not required.
2. It should use an open standard. That way, if the utility does at some point no longer receive updates and will not function with a future OS version, some other utility being able to handle the open standard could keep archives accessible.
3. Encryption should be AES-256 or equivalent and not have been broken.

 

[!!!]

Are you asking about something like ZIP or 7zip? OR about software like Keka? I don't think there are many closed-source archival formats out there nowadays.