ECDSA Sign/Verify
Online ECDSA sign and verify tool supporting secp256k1 and NIST curves, key generation, message signing, and verification for blockchain transactions, API auth, and protocol debugging.
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Generate ECDSA Key Pair
Generate random private/public keys for the selected curve.
Derive Public Key from Private Key
Input an existing private key to derive its public key.
ECDSA Guide
ECDSA is a widely adopted elliptic-curve signature algorithm that offers strong security with smaller key sizes, suitable for blockchain signing, API authentication, and certificate ecosystems.
Key Features
- Supports secp256k1, P-256, P-384, and P-521 curves.
- Supports SHA-256, SHA-384, SHA-512, Keccak-256, and pre-hashed mode.
- Supports Text, Hex, Base64, spaced Hex, C array, and PEM formats.
- Covers key generation, public-key derivation, signing, and verification.
- Runs locally in browser without uploading private keys or messages.
Common Scenarios
- Blockchain transaction signing and offline verification.
- API request signing and tamper-proof validation.
- Device identity authentication and firmware integrity checks.
- Protocol debugging and cryptographic test vector validation.
Supported Curves
- secp256k1: widely used in Bitcoin and Ethereum transaction signing.
- P-256 (secp256r1): NIST standard curve for TLS and general systems.
- P-384 (secp384r1): higher security margin for strict environments.
- P-521 (secp521r1): high-security curve for long-term assurance.
Hash Guidance
- SHA-256: recommended default for most implementations.
- SHA-384: commonly paired with P-384.
- SHA-512: commonly paired with P-521.
- Keccak-256: common in Ethereum-compatible workflows.
- None: only for already pre-hashed payloads.
Security Best Practices
- Store private keys only in controlled local or secure hardware environments.
- Validate public-key provenance and fingerprint trust chain.
- Use key rotation and privilege separation in production.
- Audit and alert on verification failures.
- Avoid mixing keys and signatures across different curves.
Quick Comparison
| Metric | ECDSA(P-256) | RSA-2048 | Ed25519 |
|---|---|---|---|
| Public key size | 64 bytes | 256 bytes | 32 bytes |
| Signature size | 64 bytes | 256 bytes | 64 bytes |
| Signing speed | Fast | Slow | Faster |
| Ecosystem | Broad | Legacy | Modern |