I appreciate this. I wasn't familiar with Adi Shamir's secret sharing scheme. I found this video quite helpful in clarifying how it works for cases where only a subset of the participants are required to confirm the secret.
That was an amazing video. I understand some fundamental crypto about secret sharing with Shamir's algo and it only took 7 minutes. Oh, and in the last 30 seconds they basically explain how bittorrent missing chunks work too. Thanks!
Interesting, thanks for sharing (I too was curious).
This is my favorite video on Diffie-Hellman key exchange which is a slightly different problem (sharing a secret, without the constraint of dividing the key): https://www.youtube.com/watch?v=YEBfamv-_do (oh, hey, same channel! Guess I'll need to check out more videos from here!)
When I was doing IT support one off the trickiest things was trying to get people to stop giving me their passwords. I am not interested in that sort of liability if something gets stolen!
Related to that: why are US landlords so hot on a copy of the house key? In a genuine emergency you let yourself in with an axe, in all other cases it's just a liability with no upside.
It's more a convenience thing for the tenant. Landlord can perform maintenance without the tenant being home, and door guards are common otherwise. Plus US laws tend to give landlords more power.
HSMs make your storage more secure, but don’t really solve the problem of people having to have access to stuff. You can address those issues, but not fully, and it’s much more difficult. I’ve worked in a number of banks where my admin accounts have given me access to things like SWIFT credentials [0]. I’ve always hated having access to stuff like that, but when you start trying to figure out how to fix it you realize that no matter what you do you’re always going to have important assets protected by secrets, and people are always going to have to have some level of interaction with those secrets.
Having access to something as insanely valuable as a bank 'master key' puts the employees at risk of blackmail, extortion, etc.
That's why you have HSMs, key ceremonies, Shamir's secret sharing etc. It's not just for trust, it's also for protection of those involved.
Unauthorized wire transfers can be undone, or covered by insurance. Loss of life cannot.