I’m a happy Arq user since a few weeks back, but this scenario scares me. I have even considered using a weak password such as ”abc123” in order to prevent this issue.
Do you think you'll remember that weak password in 10 years time? Or are you thinking you'll brute force it when the time comes? In which case there's not much reason to encrypt in the first place.
I don’t know, but I definitely think it’s easier to remember that string than a 30 characters long random string. I could even use my given name to make it more memorable.
To clarify: I didn’t primarily choose my backup application because it encrypts the backups but because it seemed like a reliable application with a solid user interface. (In Arq, encryption is not optional.)
Easy, tattoo your public and private keys on your body somewhere, maybe as QR codes.
Joking aside, I do use some things like hashes of works of literature and other important things to me as keys and archive hashes as their own passwords. I also send emails to myself explaining my thinking when I make certain decisions. It's like commenting my life.
And if I lost my memories, would I really selectively miss the data that belonged to former me? That's a scenario to think about.