Encryption

• Symmetric (fast but risky)

• Asymmetric (slow but safer)

• Hybrid encryption (fast AND safer):

• First a symmetric secret (a.k.a. session) key is randomly generated and used to encrypt data. Then the recipient's public key is used to encrypt the session key. The encrypted data and session key is safely sent to the recipient who uses his private key to first decrypt the session key then uses the decrypted session key to decrypt the data.

• See “block cipher modes of operation” next