Key Calendar for Physical Security

  1. You do not need to involve or inform any other people to transfer bitcoin to an attacker’s address. Bitcoin transfers are private.
  2. You can transfer a fortune in bitcoin within a few minutes. Bitcoin transfers are fast.
  3. Bitcoin transfers are irreversible.
  1. You can spend the coins immediately.
  2. You can spend the coins at the end of one year.
  1. Oracle has a list of 30 secrets. It switches to the next secret every day. After the final secret it switches back to the first secret.
  2. You send a secret to the Oracle, and ask to make a public key.
  3. The Oracle combines your secret with the Oracle’s secret for that day. Oracle uses a secure hash to combine the Oracle secret and your secret. (Let’s say the secret is an ECIES private key.)
  4. The Oracle sends you back the corresponding public key.
  5. You encrypt your file to the public key and delete the original.
  6. Now you have to wait until 30 days pass and the Oracle returns to the correct secret, so that you are able to obtain your key. If you do not obtain the secret, the window closes at the end of the day for 30 more days.
  7. Attacker cannot get your private key from the oracle before robbing you because they do not have your secret.
  • Oracles could publish a PGP public key each day, and make the corresponding private key accessible one year later. If you wanted to lock your coins for a shorter time, just pick an older PGP public key, for example pick one published 335 days ago so that you can get the private key in 30 days.
  • For redundancy you could encrypt your private key with PGP keys from several different Oracles.
  • Wallets could handle all of this time-locking behind the scenes and simply present the user with a “lock coins for x days” interface.
  • Locking can occur on a per-utxo basis, so you could stagger your utxos on the calendar. E.g. you could give yourself access to a different chunk of bitcoin each month for 12 months.
  • If you find that you need to sell a bunch of bitcoin, but yours are all locked up, you can always use loans and futures contracts.
  • An alternative to CLTV for a backup spend method could be something like an M of N Shamir scheme with shards at several bank deposit boxes, lawyer, etc.
  • Oracle’s could get paid for private keys with lightning, and use lightning capacity as an anti Sybil proof.
  • This idea is very private and decentralized. For example, the Oracle has no insight into who uses the service, or how much money is being protected.

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