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You can imagine how this would work trivially with lawyers (acting as executors/trustees, as they often do). Take your secret key, split it into N pieces, crea

You can imagine how this would work trivially with lawyers (acting as executors/trustees, as they often do). Take your secret key, split it into N pieces, create M parity pieces, RAID-style, for redundancy, distribute to M+N lawyers with instructions to reveal in 10 years. Lawyers put them into safe-deposit boxes for the duration, reveal in 10 years. A mildly eccentric person could even do this at scale: create a public/private keypair for every year for the next, say, century, publish the public keys, distribute the private key pieces with instructions to a wide range of lawyers. Members of the public can encrypt and publish data with the appropriate public key, assuming they trust the system.

osteele 9y ago
Shamir's Secret Sharing (SSS)[1] is a technique for doing this. SSS solves a harder problem than (my understanding of) RAID parity: that it requires not just k out of i pieces (your N and M+N) to assemble a secret, but also that no fewer than k pieces is sufficient, for arbitrary 0 < k < i. These days, SSS is commonly recommended (I don't know whether it's also commonly used) for storing cryptocurrency wallet backups. [1]: https://en.wikipedia.org/wiki/Shamir%27s_Secret_Sharing https://en.wikipedia.org/wiki/Shamir%27s_Secret_Sharing