I'm looking for a note keeper with password option

[BF Bob]

Can anyone suggest a hierarchical tree-based note keeper that will let me password protect individual folders on the tree. Not every folder would be password protected, but the ones that are would need to have different passwords.
Something like Mempad but with the password options.

Freeware and portable would be best, but other options are appreciated.

Thanks

[Nh]

http://portablefreeware.com/index.php?sc=93

[webfork]

QOwnNotes might also work given that it can provide security and synchronization between machines like other password managers.

https://www.portablefreeware.com/index.php?id=2816