deadman-10

What it is

A small, durable dead-man switch in one static Go binary. If you stop
checking in, your age-encrypted file or folder is released to a beneficiary who
can open it — and in durable mode it can release itself with no server and
no operator alive.

The switch only ever holds ciphertext it cannot read. Compromise the host
and you get encrypted bytes and public keys — nothing readable, and nothing that
lets anyone forge a vault in your name.

How it separates the concerns

• Confidentiality — the vault is encrypted to the beneficiary's key; the host

keeps only public keys. Private keys are printed once at setup and stored offline.

• Integrity — sealed with an offline owner signing key, so the beneficiary can

reject a forged substitute.

• Liveness — a check-in timer decides when to release.

Durable mode (the interesting part)

The vault key is split K-of-N with Shamir's Secret Sharing, and exactly one
share is timelock-encrypted to a future drand round. The
beneficiary holds the other K−1 offline. When the round arrives, that one share
becomes world-readable — and reveals nothing on its own. Only someone who also
holds the beneficiary's shares can reconstruct the key.

So the release survives your death, the host's death, and the bill lapsing —
while never broadcasting your secrets to the world. Verified end-to-end against
the live drand beacon, with optional permanent delivery via Arweave.

  while you check in ............ nothing happens
  you go quiet ................... WARN, escalating reminders
  you stay quiet ................ FIRE: the encrypted vault is released
  beneficiary (and only them) ... decrypts it

MIT licensed. One binary, no runtime deps.