G21 · Design Google Pay Transactions G21 · 设计 Google Pay 交易
Verified source经核实出处
Google Pay architecture referenced in Google Cloud blog. Credibility A.
Key decisions关键决策
- **Tokenise PAN** on device via EMV Payment Tokenisation; real PAN never leaves issuer.**PAN token 化**（EMV），真 PAN 不离发卡行。
- **Double-entry ledger** with exactly-once guarantees via idempotency keys.**复式账本** + 幂等键保 exactly-once。
- **ML fraud scoring** pre-authorisation; borderline goes to step-up auth.**ML 风控**：授权前评分；灰度样本走加强认证。
- **Reconciliation pipeline** with card networks.**对账管道**与卡组织。
Follow-ups追问
- Offline payment? tokenised cryptogram valid for N seconds offline.离线支付？token cryptogram 离线 N 秒有效。