Security & Recovery

Purcius Genesis mints your operator root — a single Ed25519 key that is your identity on the Purcius platform. It anchors your FQDN (published as _key.<your-fqdn>), and everything the platform trusts about you chains back to it.

It was born on your own device, in airplane mode — never on a shared machine, never handed to you by anyone. You generated it, you split it, you hold it. That is what makes it sovereign.

This key is the root of trust. It is not a password you can reset — it is the thing every other credential is measured against.

• If it leaks, someone could impersonate you as an operator. There is no higher authority to appeal to — you are the authority.
• If it is lost with no way back, your operator identity cannot be reconstructed and must be re-established from scratch.
• That is exactly why Genesis never lets the whole key exist in one place after you mint it — see below.

Treat it like the master key to everything you build. Because it is.

Born cold (air-gapped)

The key is generated only while your device's radios are off. The app refuses to mint until airplane mode is on. No network path exists at the moment of birth, so nothing can exfiltrate it.

Split, so no single loss is fatal (Shamir 3-of-5)

Your 64-byte root is mathematically split into 5 shares. Any 3 reconstruct it. Any 2 reveal absolutely nothing — not part of the key, not a hint, mathematically zero information. So you can lose up to 2 shares and still recover, and an attacker who steals 1 or 2 shares gains nothing.

Wiped the instant it is split

The moment the shares are produced, the whole key is erased from the device's memory. After Genesis finishes, the complete key does not exist anywhere — only the shares do.

The app cannot phone home

Purcius Genesis declares no network permission and makes zero connections. It is pure C — the same crypto substrate, audited and self-testing, on Android, iOS, and the command line. On launch it runs a self-test and shows you ✓ selftest PASSED before you trust it.

Public out, secret stays in

The only things you publish are public: your operator.pub and your _key.<fqdn> line. The private root never leaves your device un-split.

• Scatter the 5 shares to 5 separate places. Different physical locations, different media, different people if you like. Never store two shares together — that is what defeats the whole design.
• Keep at least 3 recoverable. You need any 3 to rebuild the key. Losing 3 or more means the root is gone.
• Publish your _key line + pubkey. That is how the world verifies you. Then leave airplane mode.
• Never type a share into a networked app or photograph them together. Move them offline, one at a time.

If you lose your device or need the key again, gather any 3 of your 5 shares and recombine them in airplane mode:

• In the app: use Recover, add 3 shares, and it reconstructs your root on-device (then re-split or re-secure it).
• On the command line (Termux / any computer, offline):
  ./genesis-cli recover out.key share-01.share share-03.share share-05.share

The recovered key's public half will match your published operator.pub — that is your proof the recovery is correct. Do it offline; wipe or re-split when done.