Identity protocol v1
A SIN ("System Identification Number") is the unique record identifier by which this identity will be known.
- Has some creation cost
- Sacrifice may be digitally proven, bootstrapping root of trust from blockchain data
- Start as anonymous; opt out of anonymity by attaching identifying key-value pairs (real.name = "John Smith", gov.us.ssn = "123-45-6789").
- Forms the basis of distributed reputation systems
- Third parties may offer digital attestions: Identity Verification, Inc. digitally signs a SIN as passing their Not A Criminal/Level-1 check.
- Controlled by the SIN's owner (key holder) at all times.
Creating sacrifice transactions
An implementation of Announce/Commit Sacrifices. That author's feedback on this protocol was very helpful.
- MPK = master public key
- TM = current block height
- Create and sign transaction T2. Broadcast if desired.
- must include Hash160(MPK) OP_TRUE anyone-can-spend output with value >= 0.001BTC
- nlocktime = TM + 144 blocks
- no more than 1000 bytes in size
- Create, sign and broadcast transaction T1
- must include OP_RETURN serialized(T2) output as last txout
Creating a SIN
- Prefix = 0x18
- SIN_Version = 0x01, similar to how UUIDs' form is dictated by a UUID's self-identified version
- MD = Hash160(MPK)
- SIN = base58_encode_check( Prefix + SIN_Version + MD )
- Hyphenate or space SIN for easier human reading
Validating the root identity information
- B1 = block w/ T1
- B2 = block w/ T2
- Verify B2 height - 144 >= B1 height.
- Verify announced T2 is valid
- Verify mined T2 spends same inputs as announced T2 (not equal to account for Transaction Malleability)
- Fail and waste sacrifice if not.
Thus a minimal root record is MPK and is provably
- linked to the sacrifices
- MPK starts a new chain of digital signature trust, for further record updates
After that root identity is created, additional key-value pairs may be associated with the root record via updates verified by MPK, stored in an alt-blockchain or DHT somewhere. That is outside the scope of this minimal document, at this time.