Introduction to Encryption - Terminology and Technology

Explain symmetric and asymmetric encryption, their key exchange tradeoffs, and how public key infrastructure with X.509 certificates enables secure email and file encryption.

Hybrid encryption combines a symmetric session key with public key encryption to secure data. Decrypting requires first unlocking the session key with a private key, then decrypting the data.

Explore password-based encryption, where a symmetric key derives from a user password via key derivation functions. Learn how salts and iterations mitigate brute-force attacks and protect private keys in files.

Explore the parameters of symmetric encryption, including block length, modes like ECB and CBC, IV, padding (PKCS7), and key sizes, contrasted with asymmetric key pairs.

Understand how password-based encryption derives a key from a strong password via hashing with salt. Use fresh salts, adequate iteration counts, and established schemes over ad hoc methods.

Explore cryptographic key formats across soft and hardware tokens, including PKCS12 and OpenPGP, and learn why password-based keys require stored cryptographic parameters to enable decryption.