I created an encryption plugin for WordPress this evening. I'm not sure if I'll try to sell it, give it away, or keep it for my personal use only.

The way it works is you highlight text in the editor (classic or block) that you want to encrypt, press a button, enter a passphrase, and it encrypts client side. Then you save your post as normal which saves the encrypted content. At this point you have encrypted data in your database keeping your private content extra secure. If you want to decrypt, you load the encrypted post, highlight the encrypted content, and press decrypt. Enter the same passphrase, and now the text is back to normal.

This gives you end-to-end encryption. What you send to the database is encrypted, what's in the database is encrypted, and what you see when you load the post is encrypted.

Currently you cannot encrypt/decrypt from the front end; this is for admin/back end use only.

Is handling the actual encryption/decryption client side the most secure way? Maybe, maybe not.
But, could someone instead have a server side solution that is even less secure than what I made? Yes.
Does doing it this way at least mean that even as data is being sent to the database if it were to be intercepted it would already be encrypted? Yes.
Is it good for a personal blog wanting to encrypt a few private thoughts from time to time? Yes.

No matter what, it adds one more layer of security to keep certain content safe from most prying eyes.

If you're interested in obtaining a copy of this plugin, let me know.