Signing and Verifying
This page allows you to digitally sign messages and verify signatures using both asymmetric (RSA, Ed25519, ECDSA) and symmetric (HMAC) cryptographic algorithms.
- Asymmetric signing uses public/private keypairs
- Symmetric signing (HMAC) uses a shared secret
- Supports RSA-PSS, Ed25519, ECDSA (P-256, P-384), and HMAC (SHA-256, SHA-512)
Features:
- Select signing algorithm
- Input private/public keys (asymmetric) or secret (symmetric)
- Sign and verify messages easily
- All signatures are shown in Base64 format
Private and Secure: Fully client-side — your keys and messages never leave your browser!
Need a Keypair?
You can generate RSA, Ed25519, or ECDSA keypairs on our Keypair Generation page
Supported Signing Algorithms
| Algorithm | Type | Use Case | Notes |
|---|---|---|---|
| RSA-PSS | Asymmetric | Digital signatures, document signing | Modern secure RSA-based signing (uses randomized padding) |
| Ed25519 | Asymmetric | High-speed signatures, modern apps | Very fast, very secure; great for APIs, tokens, blockchain |
| ECDSA | Asymmetric | Mobile, IoT, web tokens | Efficient curve-based signatures; P-256 and P-384 supported |
| HMAC-SHA256 | Symmetric | API request signing, token auth | Shared secret signing; simple, fast, widely used |
| HMAC-SHA512 | Symmetric | Long-term key signing, stronger API auth | Same as HMAC-SHA256 but stronger output (512 bits) |
Notes:
- Asymmetric signing uses a private key for signing and a public key for verification.
- Symmetric signing (HMAC) uses a single shared secret for both signing and verifying.
- RSA-PSS and Ed25519 are highly recommended for modern cryptographic signatures.
- HMAC is extremely common for internal systems, webhooks, and API authentication.