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RSA Public Key

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Paste your RSA public key in PEM format

Input Text

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RSA Encrypted Result

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RSA Encryption Information

RSA is an asymmetric encryption algorithm. It can only encrypt small amounts of data (typically up to 245 bytes for 2048-bit keys). For larger data, use hybrid encryption with AES.

RSA Encryption: Encrypt Data with RSA Public Key Online

Secure your sensitive data with RSA public key encryption using our professional asymmetric encryption tool. RSA encryption provides secure data transmission, key exchange, and confidential communication using mathematically linked public-private key pairs. Our tool supports all RSA key sizes (1024, 2048, 4096-bit) and padding schemes (PKCS#1, OAEP, PSS) for maximum security and compatibility.

Why Use RSA Public Key Encryption?

  • Secure Key Exchange: Safely exchange encryption keys over insecure channels without prior shared secrets.
  • Asymmetric Security: Different keys for encryption (public) and decryption (private) enable secure communication.
  • Digital Trust: Public keys can be shared openly while private keys remain secret for secure communication.
  • Enterprise Integration: Compatible with PKI systems, SSL/TLS, and enterprise security infrastructures.
  • Hybrid Cryptography: Often used to encrypt symmetric keys for bulk data encryption.
  • Authentication: Verify sender identity when combined with digital signatures.
  • Standards Compliance: Follows industry standards for government, financial, and enterprise applications.
  • Cross-Platform Security: RSA encryption works across all platforms and programming languages.
  • Privacy Protection: All encryption happens locally - public keys and data never leave your browser.

How RSA Encryption Works

  • Enter your plaintext data or upload files to encrypt.
  • Provide the recipient's RSA public key in PEM or other standard formats.
  • Choose the appropriate padding scheme (OAEP recommended for new applications).
  • The tool validates the public key and encryption parameters.
  • Data is encrypted using the RSA algorithm with your specified settings.
  • Download encrypted data or copy the encrypted text for transmission.
  • Only the holder of the corresponding private key can decrypt the data.

RSA Encryption Example

Plaintext: "Confidential Business Data"
RSA Public Key: 2048-bit
Padding: OAEP with SHA-256

Encrypted Output:
4A8F2E1D9C7B5A3F8E6D4B2A9C7E5F3A1B8D6F4E2C9A7B5D3F1E8C6A4B2D9F7E5A3C1B8F6D4E2A9C7B5F3D1E6A8C4B2F9D7E5A3B1C8F6D4A2E9C7B5D3F1A8E6C4B2D9F7E5A3C1B8D6F4E2A9C7B5F3D1E8A6C4B2F9D7E5A3B1C8F6D4A2E9C7B5D3F1E8A6C4B2D9F7E5A3C1B8F6D4E2A9C7B5F3D1E8A6C4B2F9

RSA Padding Schemes Explained

PKCS#1 v1.5

Traditional RSA padding scheme. Widely supported but vulnerable to certain attacks. Use for legacy compatibility only.

OAEP (Optimal Asymmetric Encryption Padding)

Modern, secure padding scheme resistant to adaptive chosen-ciphertext attacks. Recommended for new applications.

PSS (Probabilistic Signature Scheme)

Advanced padding for digital signatures providing enhanced security properties and future-proof design.

No Padding (Raw RSA)

Direct mathematical operation without padding. Only for specific cryptographic protocols, not general encryption.

Use Cases & Applications

  • Secure Communication: Encrypt confidential messages and documents for secure transmission.
  • Key Exchange: Securely exchange symmetric encryption keys for bulk data encryption.
  • Email Security: Encrypt emails using PGP/GPG or S/MIME for confidential communication.
  • API Security: Encrypt sensitive API payloads and authentication tokens.
  • Database Protection: Encrypt sensitive database fields and configuration data.
  • Cloud Security: Encrypt data before uploading to cloud services for privacy protection.
  • Financial Services: Protect banking data, payment information, and financial transactions.
  • Healthcare Systems: Encrypt patient records and medical data for HIPAA compliance.
  • Legal Documents: Secure contracts, agreements, and confidential legal communications.
  • IoT Security: Encrypt device communications and configuration data for Internet of Things.

Frequently Asked Questions (FAQs)

1. What's the difference between RSA encryption and symmetric encryption?

RSA uses different keys for encryption (public) and decryption (private), while symmetric encryption uses the same key for both operations.

2. Which RSA key size should I use for encryption?

Use 2048-bit minimum for new applications, 4096-bit for high security. Avoid 1024-bit keys due to security concerns.

3. Can I encrypt large files with RSA?

RSA is typically used for small data or keys. For large files, use RSA to encrypt a symmetric key that encrypts the actual file.

4. Is the recipient's public key sent to any servers?

No, all encryption happens locally in your browser. Public keys and data never leave your device for complete privacy.

5. Which padding scheme should I choose?

OAEP is recommended for new applications as it provides better security. Use PKCS#1 v1.5 only for legacy compatibility.

6. Can I encrypt data for multiple recipients?

Yes, encrypt the same data multiple times using different public keys, so each recipient can decrypt with their private key.

7. How do I verify the public key belongs to the intended recipient?

Use digital certificates, key fingerprints, or secure key exchange protocols to verify public key authenticity.

8. What formats does the tool accept for public keys?

We support PEM, DER, PKCS#1, and X.509 certificate formats. The tool can auto-detect most standard formats.

9. Can I use SSL certificate public keys for encryption?

Yes, you can extract and use public keys from SSL certificates for RSA encryption operations.

10. How secure is RSA encryption?

RSA with proper key sizes (2048+ bits) and modern padding (OAEP) is considered secure for most applications.

11. Can I encrypt binary files and images?

Yes, though typically RSA encrypts a symmetric key used to encrypt the actual file due to RSA's size limitations.

12. What happens if I use the wrong public key?

Encryption will succeed, but only the holder of the corresponding private key can decrypt. Verify keys before encryption.

13. Is RSA encryption quantum-resistant?

Current RSA is vulnerable to quantum computers. For long-term security, consider post-quantum encryption algorithms.

14. Can I combine RSA with other encryption methods?

Yes, RSA is often used in hybrid systems to encrypt symmetric keys that encrypt bulk data for optimal security and performance.

15. What browsers support RSA encryption?

All modern browsers with Web Crypto API support, including Chrome, Firefox, Safari, Edge, and mobile browsers.

16. Can I encrypt data for API transmission?

Perfect for APIs! Encrypt sensitive payloads, authentication tokens, and configuration data for secure transmission.

17. How do I handle encryption errors?

Common issues include invalid public key format, data too large for key size, or unsupported padding scheme.

18. Can I encrypt passwords and secrets?

Yes, RSA is excellent for encrypting passwords, API keys, and other secrets for secure storage and transmission.

19. Does the tool work offline?

Yes, after initial page load, all encryption operations work completely offline for enhanced security and privacy.

20. Is this RSA encryption tool free?

Yes, completely free with no registration, limitations, or subscription required. Encrypt unlimited data securely.

Conclusion

Our RSA Encryption tool provides enterprise-grade asymmetric encryption with support for all key sizes and modern padding schemes. Whether you're securing confidential communications, implementing key exchange protocols, or protecting sensitive data, our privacy-focused tool ensures your public keys and data remain secure while providing industry-standard RSA encryption. Encrypt your data with confidence—completely free, secure, and standards-compliant.