ECDSA Signer/Verifier (Web Crypto API)

About the ECDSA Tool

This tool uses the Web Crypto API to perform Elliptic Curve Digital Signature Algorithm (ECDSA) operations. You can generate ECDSA key pairs (PEM or JWK format), sign messages with a private key, and verify signatures with a public key. It supports standard curves like P-256, P-384, and P-521, along with common hash algorithms (SHA-256, SHA-384, SHA-512).

Why Use This Tool?

ECDSA is widely used for digital signatures, providing strong security with smaller key sizes compared to RSA. Use this tool to: create and verify signatures for data integrity and authenticity; generate key pairs for use in other applications (like JWTs with ES* algorithms); or experiment with ECDSA parameters for learning purposes. All operations are performed client-side.

Example Use Cases

• Generating an ECDSA P-256 key pair for signing transactions or messages.
• Signing a software update or a piece of code with your private ECDSA key.
• Verifying the ECDSA signature on a message received from a trusted source to ensure it hasn't been tampered with and that it originated from the claimed sender.

Pro Tips

• Curve and Hash: Ensure the same elliptic curve and hash algorithm are used for both signing and verification.
• Key Formats: JWK (JSON Web Key) is a standard JSON format for representing crypto keys. PEM is a common text-based format. Ensure your keys are in the selected format for input.
• Signature Format: This tool outputs and expects signatures in Base64 format (representing the DER-encoded signature bytes).