Webhook Signature Error
Pronunciation: WEB-hook SIG-nuh-cher EH-rur
Definition
A webhook signature error occurs when a receiver cannot validate the provided signature against the expected message, key, algorithm, or freshness rules. Webhook Signature Error must specify the producer, consumer, event type and version, delivery URL, stable event identifier, signature method, timestamp, retry policy, and expected response.
Overview
Meaning in plain language
A webhook signature error occurs when a receiver cannot validate the provided signature against the expected message, key, algorithm, or freshness rules. Webhook Signature Error must specify the producer, consumer, event type and version, delivery URL, stable event identifier, signature method, timestamp, retry policy, and expected response.
How it works
For Webhook Signature Error, assertions should verify final provider and business state, not only an HTTP status or locally mocked response. Webhook Signature Error is a verification failure state whose cause may be wrong raw bytes, secret, algorithm, encoding, timestamp, or key rotation rather than a provider outage. A sudden error spike may indicate configuration drift, proxy changes, provider rotation, or active attack. Receivers should reject safely, return the documented status, record sanitized reason and correlation data, and alert on abnormal rates. Recovery for Webhook Signature Error should combine replay controls with an authoritative status check rather than trusting delivery history alone.
Monitoring for Webhook Signature Error should track delivery age, signature failures, duplicate rate, retry exhaustion, and unresolved business events.
Where people get it wrong
Troubleshooting should compare signing input bytes, algorithm, timestamp and secret version without logging the secret itself. Re-signing parsed JSON often changes its bytes.
Related concepts
Webhook Authentication, Security Incident, Webhook Verification.
Reference
Example
A webhook is rejected because the computed HMAC differs from the header value. The cause could be a wrong secret, altered JSON whitespace, incorrect byte encoding or a truly forged request.
Comparison
A failed verification is a signal to reject and investigate a message, not proof that its claimed blockchain event is false.
Key Takeaway
Signature errors must fail closed, preserve safe diagnostics, trigger investigation, and never expose keys or silently disable authentication.
Sources
- NIST Documentation: Cryptographic Standards And Guidelines — NIST (2026-07-30)
- OxaPay Documentation: Webhook — OxaPay (2026-07-30)
- Stripe Documentation: Webhooks — Stripe (2026-07-30)