What is RSA Encryption?
RSA (Rivest-Shamir-Adleman) is an asymmetric encryption algorithm developed in 1977. Unlike symmetric encryption, RSA uses two separate keys: a public key and a private key. Data encrypted with the public key can only be decrypted with the corresponding private key, making it ideal for secure key exchange and digital signatures.
How RSA Works
- Key Pair Generation: Mathematically linked public and private keys are generated
- Public Key Distribution: Public key can be shared safely
- Encryption: Sender encrypts message using recipient's public key
- Decryption: Only the recipient's private key can decrypt the message
- Security: Private key cannot be derived from public key
RSA Use Cases
- Secure connections in SSL/TLS certificates
- Email encryption (PGP, S/MIME)
- Digital signatures and authentication
- VPN and secure remote access
- Blockchain and crypto wallets
- Software licensing and code signing
RSA-2048 Security Level
RSA-2048 uses a 2048-bit key length, currently considered standard security:
- Provides 112-bit security level (equivalent to AES-128)
- Considered safe until at least 2030 (NIST recommendation)
- Practically impossible to break with current computers
- Vulnerable to future quantum computers
RSA vs AES
RSA and AES serve different purposes:
- RSA: Small data encryption, key exchange, digital signatures
- AES: Large data encryption, file and disk encryption
- Hybrid Approach: Encrypt AES key with RSA, then encrypt data with AES
- Speed: AES is faster, RSA is slower
- Key Management: RSA simplifies key distribution
Private Key Security
Your private key is the foundation of your security. Never share it, send it via email, or store it insecurely. If compromised, all data encrypted with its public key is at risk. Use a secure password manager or hardware security module (HSM) to protect your keys.