This article explains the technical mechanism behind WeChat's offline payment, detailing how a time‑based one‑time dynamic code is generated on the device, verified by the server, and destroyed to protect user accounts even without network connectivity.
This article explains the technical principles behind offline payment codes used by Alipay and WeChat, covering common payment modes, online and offline code schemes, OTP generation, cryptographic algorithms, their advantages, drawbacks, and practical implementation details.
Even without network connectivity, mobile payment apps like WeChat and Alipay can complete transactions using offline payment codes; this article explains the two common QR payment methods, the online and offline code schemes, the underlying OTP and HMAC‑SHA1 algorithms, and their security trade‑offs.
This article explains the two main mobile payment methods, details the online and offline payment‑code schemes, describes the OTP generation algorithm based on HMAC‑SHA1 and BASE32, and discusses the security trade‑offs and practical considerations of offline payment codes.
