RSA Encrypt / Decrypt

Generate RSA key pairs (1024–4096 bit) and encrypt or decrypt with public/private keys. RSA-OAEP with SHA-256.

Cryptography
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🔑 Key Management
⚠️ Never share your private key. Blurred for security.
🔒 Encrypt with Public Key
🔓 Decrypt with Private Key
💡 Async Generation Key generation runs in background workers — the page stays responsive even for 4096-bit keys.

Common use cases

Frequently asked questions

What size RSA key should I use?

2048 bits is recommended. 4096 bits provides higher security but is slower. 1024 bits is too weak for new applications.

Why can RSA only encrypt small messages?

RSA encrypts a single block. For 2048-bit keys, the maximum is about 190 bytes. For larger data, encrypt with AES, then encrypt the AES key with RSA (hybrid encryption).

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