Payloads are signed using asymmetric A.K.A. public-key cryptography to guarantee the authenticity of delivered callbacks. Each callback delivery request includes an X-Signature header field. This field contains a base64-encoded RSA PKCS#1 v1.5 signature of the SHA256 digest of the request body buffer. You can obtain the public key for Webhook authentication from Webhook.public_key of the corresponding Webhook. You can obtain the public key for success callback authentication from GET /public_key/. Please note the provider is not responsible for any financial losses incurred due to not implementing payload signature verification.