RSA / Public-Key

Encrypt messages with an RSA public key.

Public Key (PEM)

Plaintext

Note: RSA-OAEP with SHA-256 is used. Messages longer than about 190 bytes are split into chunks automatically. All processing runs locally in your browser.

What Is a RSA / Public-Key?

The RSA / Public-Key tool encrypts messages with an RSA public key. Anyone can encrypt with your public key, but only the matching private key can decrypt — this is the foundation of public-key cryptography.

How to Use This RSA / Public-Key

1
Paste Public KeyPaste a PEM public key (BEGIN PUBLIC KEY).
2
Enter TextType the message to encrypt.
3
EncryptClick Encrypt to produce base64 ciphertext.

Frequently Asked Questions

Generate one with the RSA Key Pair Generator, or use the public key someone shares with you. Publish your public key freely; it is meant to be public.

Yes. A 2048-bit RSA-OAEP key holds about 190 bytes per operation, so longer messages are automatically split into multiple chunks.

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