Claim Spec v1 (BTC → bit2coin)

Overview

BTC holders can claim bit2coin allocations non-custodially by proving ownership of BTC addresses at snapshot height H.

Supported address types

• Legacy (P2PKH), P2SH, SegWit (P2WPKH/P2WSH), Taproot (P2TR).

Proof of ownership

• Sign a domain-separated message with the BTC private key corresponding to the address.
• Suggested message format (ASCII):
• "bit2coin-claim:v1|chain-id=|claim-to=|btc-addr=|nonce="
• The signature is verified against the BTC address type rules.

Anti-replay

• Domain separation via the fixed prefix and chain-id.
• Nonce prevents cross-claim reuse.

Claim flow

1. User inputs BTC address and target bit2coin address.
2. Tool generates the exact message; user signs via hardware wallet/CLI.
3. Submit signature + Merkle proof of balance to the claim contract/module.
4. Module mints or unlocks allocation to the bit2coin address; records that BTC address as claimed.

Merkle proofs

• Snapshot computation maps each BTC address to its balance; tree root published.
• Claim includes path proof verifying the entry against the published root.

Safety guidelines

• Never request a spend transaction, only message signatures.
• Publish open-source CLI and audited web app; provide test vectors.