HMAC-SHA1 Generator

Generate HMAC-SHA1 keyed-hash message authentication code for API and message verification.

Secret Key
Enter your secret key
Message
Enter text to authenticate
HMAC-SHA1
160-bit authentication code

What is HMAC-SHA1?

HMAC-SHA1 combines SHA-1 hash function with a secret cryptographic key to provide message authentication. It verifies both data integrity and authenticity.

Key Features

  • Message Authentication: Verifies integrity and authenticity
  • Secret Key Required: Uses a shared secret key
  • Fixed Output: 160-bit hash (40 hex characters)
  • Widely Supported: Implemented in most crypto libraries

Common Use Cases

  • API Authentication: Verify API requests and responses
  • JWT Tokens: Sign JSON Web Tokens
  • AWS S3 Signatures: Authenticate cloud storage requests
  • OAuth: Used in OAuth 1.0 signatures
  • Webhook Signatures: Verify webhook authenticity

Security

While HMAC-SHA1 is more secure than SHA-1 alone due to the secret key, for new applications consider using HMAC-SHA256 or HMAC-SHA512.

Example

Message: Hello, World! Secret Key: secret-key-123 HMAC-SHA1: Authentication code generated from message and key