Casa performs annual stress tests on seed phrase backups.
Some self-custody services, like Casa, offer multi-signature setups that reduce the risks of single-point failure. A multi-key crypto "vault" can include mobile phone keys, multiple hardware keys, and a recovery key that a company likes Casa holds on an owner's behalf.
The multi-sig custody approach allows an owner to hold a majority of keys while a trusted partner holds a minority of keys. John Haar, managing director at Swan Bitcoin, says that in such a setup, the owner would need to lose all the physical devices and all copies of the seed phrases at the same time. As long as the owner can access at least one device or one seed phrase, they would be able to recover their bitcoin. This approach should significantly limit the potential for all of the devices to be lost in an event like a natural disaster, Haar said.