ECDSA Verify Signature
Verify ECDSA signatures using the original message, curve, hash algorithm, public-key format, and Hex or Base64 signature. Read more
Verify an ECDSA signature online
ECDSA verification checks whether a signature matches the supplied message, public key, curve, and hash algorithm. A valid result confirms integrity and possession of the corresponding private key, assuming the public key itself is trusted.
Verification does not establish the identity behind an unknown key. Obtain the public key or certificate through an authenticated channel and apply the trust policy required by your application.
How to verify ECDSA
- Enter the original message and select its byte encoding.
- Choose the exact curve and digest used by the signer.
- Paste the public key as PEM, Hex, or Base64.
- Select the signature encoding and paste the signature.
- Verify; treat every mismatch or parsing error as a failed signature.
Why verification fails
Common causes include a changed message byte, wrong curve, different hash, incorrect public key, incompatible key representation, or a Hex/Base64 mismatch. secp256k1 and P-256 keys are not interchangeable.
NIST FIPS 186-5 defines ECDSA generation and verification. A valid signature does not mean the signed content is safe or authorized; it only proves the cryptographic relationship being checked.
ECDSA verification FAQ
Can a signature be verified without the original message?
No. Verification hashes the exact message bytes and compares them through the signature algorithm.
Does a valid signature reveal the private key?
No, provided signing used a sound implementation and nonce generation.
How do I generate compatible keys and signatures?
Use the ECDSA Key Generator and ECDSA Sign Message with matching curve, formats, and digest.