What would happen to your cryptocurrency holdings if something bad happened to you? No one is protected against death, memory loss, or any other terrible accident, so Bitcoin entrepreneurs Matt Odell and Murtaza Ali have launched an elaborate "dead-mans" protection switch called FinalMessage.
FinalMessage is a crypto messaging service which sends a message to your trusted friend or partner in case something happens to you, and you stop engaging with the switch. In such case, you could pass one last "cryptographically secure message" to the people you care about – be it your private keys, will, or any other private information.
According to the service’s creators, that is the intended use case, but the actual implications of the service are limited only by the user’s creativity.
As explained on the project’s website, the service sends 1 of 3 Bitcoin multisignature keys to your recipient in the event of an emergency. The system assumes emergency event if you stop paying for the subscription.
A message uses SHA256 hash, which is used in digital signatures, message authentication codes, and is encrypted in the user’s browser together with a password before being sent to FinalMessage’s servers. The Bitcoin network acts as a trigger mechanism for the messages. It works with both Bitcoin and Bitcoin’s lightning network.
If you stop paying us, the switch expires, and the email is sent out to the designated recipient.
— Matt Odell (@matt_odell) April 23, 2019
The system is built with as minimal trust as possible and works the following way:
At the moment, the service will cost you up to USD 50 per year for a single emergency message, and there is no option to cancel your switch, so be mindful if you choose to set up one.