ECDH
Compute a shared secret from your private key and a peer public key (P-256). Paste your data, then click to dissect it. Everything runs on your device, nothing is sent to a server.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
(keys in More settings)
Example Output
Shared secret (hex): 4a8c…
How to Use
- 1Paste your data (PEM/Base64/token) into the Input field.
- 2Click the button (or press Ctrl+Enter) to dissect it.
- 3Read the decoded result in the Output field.
About ECDH
ECDH (Elliptic Curve Diffie-Hellman) lets two parties agree on a shared secret over a public channel without ever sending the secret. Each combines its own private key with the other's public key.
The magic: your-private-key + peer-public-key yields the SAME secret as peer-private-key + your-public-key. This tool computes it for the P-256 curve (PEM keys).
Do NOT use the raw shared secret as an encryption key — always run it through HKDF first. ECDH underpins key exchange in TLS and many secure protocols.
FAQ
Are my data or keys sent to a server?
No. ECDH runs entirely in your browser using the Web Crypto API and client-side libraries. Your data, passwords, and keys never leave your device.