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 workflows where you need a quick cryptographic operation without opening a terminal. It is not a substitute for production key management, HSMs, or audited security infrastructure. Review Utilitoo's Privacy Policy if your organization restricts browser-based crypto tools.
Common use cases
- RSA public/private key encryption - a common daily workflow on Utilitoo.
- Auditing secrets and credentials before committing code or sharing configs.
- Demonstrating rsa encrypt decrypt concepts in security training without exposing production keys.
- Quick checks on rsa encrypt decrypt output when you cannot use a local CLI tool.
- Cross-checking RSA Encrypt / Decrypt output against a colleague's result during pair debugging or code review.
Tips & common mistakes
RSA Encrypt / Decrypt is designed for development and education - never paste production secrets into any online tool unless you trust the privacy model. On Utilitoo, cryptographic operations run client-side, but you should still rotate credentials if they may have been exposed. Use generated passwords and tokens immediately and store them in a password manager rather than leaving them in browser history. RSA Encrypt / Decrypt on Utilitoo runs client-side, so keys and plaintext you enter are not uploaded for processing. Still follow your organization's policy on secrets in browser tools, rotate any credential that may have been exposed, and prefer test keys when experimenting.
Common errors
- Wrong key length or encoding - AES keys must match the selected bit size; hex and UTF-8 keys are not interchangeable without conversion.
- Algorithm mismatch - decryption fails if the mode, IV, or salt differs from what was used during encryption.
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.