RSA Encrypt / Decrypt
RSA public/private key encryption.
RSA asymmetric encryption lets anyone encrypt a message with a public key while only the private key holder can decrypt it - the foundation of secure communication, digital signatures, and TLS. Utilitoo's RSA Encrypt/Decrypt tool generates 2048-bit key pairs in your browser and supports encrypt-with-public / decrypt-with-private workflows.
Developers learning public-key cryptography, security testers validating encryption integrations, and students studying CS fundamentals all benefit from an in-browser RSA playground. Generate keys, encrypt a message, and decrypt it to verify the round trip.
Click Generate key pair for fresh base64-encoded public and private keys. Encrypt a message with the public key, then decrypt the ciphertext with the private key. Pair with AES Encrypt/Decrypt for symmetric workflows or JWT Decoder for token inspection.
All key generation and encryption uses the Web Crypto API locally on Utilitoo. Keys and messages are never uploaded. Free for learning and testing - not audited for production security.
RSA Encrypt / Decrypt supports learning and development crypto tasks: RSA public/private key encryption. It is not a substitute for production key management or HSMs. Prefer disposable test material.
Common use cases
- Generating or checking rsa encrypt decrypt values while building auth and crypto features.
- Practicing rsa encrypt decrypt workflows in training labs without touching production secrets.
- Spot-checking hashes, tokens, or passwords during code review dry-runs.
- Comparing RSA Encrypt / Decrypt output with a CLI result when onboarding a new crypto library.
- Creating throwaway test credentials that should never ship to production.
Tips & common mistakes
RSA Encrypt / Decrypt is for development and education - avoid production secrets unless your policy allows browser crypto tools. Operations run client-side on Utilitoo, but rotate anything that may have been exposed on a shared machine. Store generated values in a password manager instead of browser history.
Common errors
- Unexpected RSA Encrypt / Decrypt output - confirm encoding (hex vs base64 vs utf-8) and algorithm options match the other system.
- Copied trailing whitespace or line breaks from chat apps can change digests and comparisons - trim before verifying.
How to use
- Paste keys and message.
- Encrypt or decrypt.
Frequently Asked Questions
How do I generate an RSA key pair?▼
Click Generate key pair in Utilitoo to create 2048-bit RSA public and private keys in base64 format.
What key size is used?▼
2048-bit RSA keys with OAEP padding and SHA-256 hash.
Can I use my own keys?▼
Yes. Paste existing base64-encoded SPKI public or PKCS8 private keys.
Is there a message size limit?▼
RSA encrypts small messages only. Large data should use AES with RSA for key exchange.
Are my keys uploaded?▼
No. Key generation and encryption run entirely in your browser on Utilitoo.
Related Tools
AES Encrypt / Decrypt
Encrypt and decrypt text with AES.
JWT Decoder
Decode JWT tokens and inspect claims.
SHA256 Generator
Generate SHA-256 hashes from text.
Hash Checker
Verify text against a known hash.
Token Generator
Generate secure API tokens and secrets.
Secure Random Generator
Generate cryptographically secure random values.