[mrich]

It's aes256 using openssl:

https://github.com/mrichtarsky/glacier_deep_archive_backup/b...

Does that leak information you would be concerned about?

It's always a full backup.

[GRBurst]

Nope. There are some concerns about using openssl for file encryption and it is generally good to be very specific about the encryption instead of using default parameters. I don't necessary share all the concerns, but it might be worth knowing them, e.g. https://security.stackexchange.com/a/182281

[mrich]

Thanks for the pointer. gpg is the better option then, I've switched to it.