I've been using Libreoffice to store my diary for years -- IIRC they use blowfish on the crypto side of things? I had a weird issue a while back where I'm not sure if I forgot my diary's password, or the file got corrupted.

I've had that happen a few times, each with a long space in between I keep things on paper.

It's a great project that doesn't get enough love.

Why Libreoffice? Does your diary contain advanced formatting, tables, images, or other involved content? Or just for the encryption?

I ask because I also keep a diary and have refined how I store it and secure it, over 25+ years. Only recently did I find something that I like better than paper.