Comment by cornstalks
2 days ago
I keep meaning to do something like this in combination with Shamir’s secret sharing (which allows you to split a secret into M blocks, of which any N can be combined to recover the key, and M and N are configurable) to distribute a private key among family members in case of my untimely demise so they can more easily access my financial accounts and stuff. Has anyone done that before, and if so, what tools do you prefer? My family members are nontechnical so that’s the biggest challenge.
I've seen https://github.com/cyphar/paperback before which basically does this, I believe. I haven't used it in the context of letting other people recover things though.
Visual cryptography is really cool. Shamir and Naor came up with an algorithm in the 90s: https://en.wikipedia.org/wiki/Visual_cryptography#Example
Basically hand out transparencies to n people, and they all have to overlap to see the picture. It's like magic when you're playing with them.
Codex32 allows you perform Shamir secret sharing operations and error correcting code without using a computer. Instead, you can perform the operations by hand using cardboard code wheels called volvelles.
It is a really fun idea and does not require deep technical knowledge to operate. The intent is for Bitcoin secret keys, but it can be used for any secrets.
https://secretcodex32.com/
One use that I've seen reported whas when Naomi Wu / SexyCyborg was taken into custody by Chinese gov't officials, her friends used SSS to gain access to her social media accounts to report the abduction.
superbacked, now free and open source, does exactly this.
https://superbacked.com/