Securing Webhook Pipelines Against Replay Attacks

Webhooks expose HTTP endpoints to public traffic, making them high-value targets. Without stringent validation, malicious actors can spoof events or execute replay attacks, causing duplicate transactions or state corruption.

We design a zero-trust callback pipeline by enforcing cryptographic payload signing. Using SHA256 HMAC tokens, the receiving server validates the origin of every incoming payload against a shared rotation key.

To prevent replay attacks, every signature is verified against a database cache of recently processed IDs. If a request is valid but downstream processing fails, the worker transfers the payload to a queue for automatic retries.