Encryption for Nemo

Is there an encryption extension or tool for Nemo in the Ubuntu repository ?

Do you mean something like this?

More like the following. I was hoping for something from the official repo .

nemo-seahorse is an extension for Nemo which allows encryption
and decryption of OpenPGP files using GnuPG.

nemo-seahorse is a fork of seahorse-nautilus 3.3.1.
https://github.com/linuxmint/nemo-extensions/tree/master/nemo-seahorse

If you are referring to the Universe repository - nemo and related stuff are maintained by the debian cinnamon team. Probably the best way to request a new cinnamon package such as nemo-seahorse is via their mailing list debian-cinnamon@lists.debian.org