Datamynt Protocols

Open specifications for blockchain-anchored verification on Bitcoin SV.

These protocols share a common cryptographic foundation: HKDF-SHA256 key derivation from identity to Bitcoin address. This means anyone can independently verify proofs and contracts — no server, no database, no trust required. Only math.

Protocols

BEVISET.md — Digital Ownership Certificates

Register, verify, and transfer ownership proofs anchored as 1SatOrdinal inscriptions.

• HMAC-peppered identity hashing (rainbow table resistant)
• 1SatOrdinals: the proof IS a satoshi, transferable via UTXO chain
• Independent verification without any server

The proof is a satoshi. The owner holds the satoshi. The UTXO chain IS the ownership history.

HELTENIG.md — Digital Contract Signing

Two-party contract signing with blockchain anchoring. One inscription per signer.

• Ricardian contract templates with party-tagged fields
• Contract text hashed, never stored on-chain
• Each signer holds their own inscription as a UTXO

The contract hash proves what was agreed. The UTXO proves who agreed. The blockchain proves when.

Shared foundation

Both protocols use the same key derivation algorithm (HKDF-SHA256, RFC 5869) with independent domain separators per service. The same identity produces different Bitcoin addresses for Beviset and Helt Enig — by design.

Identity (BankID PID or email+phone)
    │
    ├─ domain: "beviset-v1-keygen"    → Beviset address
    ├─ domain: "heltenig-v1-keygen"   → Helt Enig address
    └─ domain: "yourapp-v1-keygen"    → Your service's address

The algorithm is published. Anyone can derive the address from an identity claim and verify it against the blockchain.

Quick reference

import hashlib, hmac

# Identity hashing (shared pepper for BankID)
PID_PEPPER = "beviset-protocol-pid-pepper-v1-datamynt"
identity_hash = hmac.new(PID_PEPPER.encode(), pid.encode(), hashlib.sha256).hexdigest()

# Key derivation (HKDF-SHA256)
def derive_key(identity_input: str, domain: str) -> bytes:
    prk = hmac.new(domain.encode(), identity_input.encode(), hashlib.sha256).digest()
    return hmac.new(prk, b"bitcoin-key-derivation\x01", hashlib.sha256).digest()

License

• Specifications (BEVISET.md, HELTENIG.md): MIT License
• Code (implementations): Open BSV License

Links

datamynt.no · beviset.no · heltenig.no

Verification requires only math, not trust.