Payment Verification

Security Properties

• Seeders MUST verify payments on-chain (blockchain is the source of truth)
• ECDH binding prevents payment proof replay across different connections
• Nonce freshness prevents replay of old payments
• Transaction signature tracking prevents double-spending

Attack Mitigations

Fake Payment Proof

Attack: Leecher sends a fabricated channel_opened message with a fake transaction signature.

Mitigation: The Seeder fetches the transaction independently from the blockchain. It ignores the Leecher-provided amount field entirely. All validation is done against on-chain state.

Replay Attack

Attack: Leecher tries to reuse a transaction signature from a previous session.

Mitigation: The Seeder checks nonce freshness (channel opening must be within 5–10 minutes) and maintains a set of consumed transaction signatures. Any previously-used channel is rejected.

Man-in-the-Middle Attack

Attack: An attacker intercepts the connection and tries to redirect payments.

Mitigation: The ECDH key exchange ensures only the two peers with correct ephemeral keys can derive the Session_UUID. The session hash in the memo binds the payment channel to this specific connection. An attacker cannot forge the Session_UUID without knowing one of the private keys.

Peer Authentication

Payment channels require real cryptocurrency deposits, which makes Sybil attacks economically unfeasible. Each channel opening costs transaction fees, limiting spam.

Current V1 Approach

Future Considerations

• Reputation systems for seeders (based on successful channel closes)
• Rate limiting for channel creation per wallet
• Proof-of-bandwidth mechanisms if needed