RSA Tool
RSA
Generate an RSA key pair and encrypt/decrypt or sign/verify text — in your browser via the Web Crypto API.
How it works
Two people who can’t verify each other over a public channel can still communicate securely:
- Each person generates a key pair and keeps their private key secret.
- They exchange public keys — these are safe to share openly.
- To send a message, encrypt it with the recipient’s public key. Only their private key can decrypt it.
- Sign a message with your private key so the other side can verify it wasn’t altered.
- A public key alone doesn’t prove real-world identity. Compare the key fingerprint through a separate trusted channel to be sure.
My keysyours
Your identity. Share your public key freely; keep your private key secret.
My public key
My private key
Recompute my public key from the private key above.
Saved keys
Saved pairs include PRIVATE keys, stored unencrypted in this browser. Anyone with access to this device can read them.
No saved keys yet.
Protect with a passphrase
Encrypts the whole keychain at rest (AES-GCM). You will need this passphrase to unlock your saved keys — it cannot be recovered.
Recipient’s public keytheirs
Public key
Paste the public key of the person you’re writing to. Encrypting with it means only they can read the message.
Input
Encrypt uses the recipient’s public key (theirs). Decrypt uses your own private key.
Output