Silent payments (BIP-352)

Silent payments detection is not a standalone heuristic — it is built into H3 (address reuse).

How it works

When H3 detects address reuse on an input, it also checks whether any output pays to a BIP-352 silent payment address (identified by the sp1q / tsp1q prefix).

• Recipient already supports silent payments — H3's suggestion reads: "Recipient supports silent payments. Future payments to this recipient will not reuse addresses."
• Recipient does not support silent payments — H3 suggests requesting a silent payment address to eliminate reuse permanently.

What is a silent payment address

BIP-352 silent payment addresses are static addresses that derive a unique one-time on-chain output per payment. The recipient scans the chain without publishing a fresh address per transaction.

Silent payment addresses start with sp1q (mainnet) or tsp1q (testnet/regtest).

Scoring effect

Silent payment awareness does not change H3's weight (20) or severity (Critical). It adjusts the suggestion text only.