Encrypt and decrypt short text with RSA

Use this RSA tool to encrypt short text with a public key or decrypt matching ciphertext with its private key. It is intended for local testing and learning, not for handling secrets you cannot safely process in a browser.

How it works

  1. Generate or paste a compatible PEM key pair.
  2. Encrypt a short message with the public key to produce Base64 ciphertext.
  3. Decrypt that ciphertext with the corresponding private key and confirm the original message.

Capabilities and limits

  • Works with PEM key material for local RSA experiments.
  • Uses the public key for encryption and the matching private key for decryption.
  • RSA is unsuitable for large payloads; use authenticated symmetric encryption for data and protect keys carefully.

Examples

Short test message

message: deploy-ready
key: RSA public PEM

Encrypt the text, then decrypt the Base64 result using the paired private key.

Key-pair round trip

public key → encrypt → Base64 ciphertext
private key → decrypt → original text

This confirms that the public and private keys belong to the same pair.

Frequently asked questions

Can I decrypt with an RSA public key?

No. Public-key encryption is reversed with the matching private key. Signing is a separate operation with different verification semantics.

Should I encrypt passwords with RSA?

Do not design password storage around reversible encryption. Use a purpose-built password hashing system on a trusted server.