Ed25519 Sign/Verify
Online Ed25519 sign and verify tool with key generation, public key derivation, message signing, and signature validation for API security, identity authentication, and protocol debugging.
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Key Generation
Generate a new Ed25519 key pair with multiple output formats.
Ed25519 spec: private key 32 bytes, public key 32 bytes, signature 64 bytes
Derive Public Key from Private Key
Input an existing private key to derive its public key.
Ed25519 Guide
Ed25519 is a modern Edwards-curve signature algorithm with strong performance, compact key/signature sizes, and deterministic signing, widely used in API security and identity systems.
Workflow
- Generate a key pair in the key tab, or derive a public key from an existing private key.
- In the sign tab, choose message and key formats, then create a signature.
- In the verify tab, provide public key, original message, and signature to validate.
- Use copy actions to export keys and signatures quickly.
Key Features
- Supports key generation, signing, verification, and public-key derivation.
- Supports Text, Hex, Base64, spaced Hex, and C array formats.
- Runs locally in the browser without uploading private keys or messages.
- Validates key and signature byte lengths to prevent format misuse.
Technical Specifications
- Curve: Curve25519 (Twisted Edwards form).
- Private key size: 32 bytes (256-bit).
- Public key size: 32 bytes (256-bit).
- Signature size: 64 bytes (512-bit).
- Security strength: ~128-bit, commonly compared to RSA-3072.
- Standard: RFC 8032.
Common Use Cases
- SSH key authentication and secure automation.
- TLS/SSL certificate and handshake signing flows.
- Blockchain transaction signing and identity validation.
- Software package and firmware signing verification.
- High-assurance API request signing workflows.
Security Best Practices
- Protect private keys and never expose raw key material.
- Distribute and pin trusted public-key fingerprints.
- Use HSMs for critical production signing operations.
- Rotate signing keys regularly with expiration policies.
- Log and alert on verification failures in production.
Algorithm Comparison
| Metric | Ed25519 | RSA-2048 | ECDSA P-256 |
|---|---|---|---|
| Public key size | 32 bytes | 256 bytes | 32 bytes |
| Signature size | 64 bytes | 256 bytes | ~64 bytes |
| Signing speed | Very fast | Slow | Fast |
| Verification speed | Very fast | Fast | Medium |
| Deterministic signing | Yes | Yes | Requires randomness |