Hybrid Encryption

is a cryptographic approach that combines the benefits of both symmetric and asymmetric encryption.

• Symmetric: the same secret key is used for both encryption and decryption.
• Asymmetric: uses a pair of keys; public (encrypt) and private (decrypt).
• Common steps:
  1. The sender obtains the recipient’s public key (ex: Browser from a web server).
  2. A random and temporary symmetric key is generated by the sender (to encrypt the data).
  3. The sender encrypts the data with the symmetric key.
  4. The symmetric key is encrypted with the recipient’s public key.
  5. The encrypted data and the encrypted symmetric key are sent to the recipient.
  6. The recipient decrypts the symmetric key using their private key and uses it to decrypt the data.
• Examples: SSL/TLS (HTTPS), PGP, SSH, IPsec, S/MIME