1. Symmetric Key Algorithms
   1. Symmetric Key Algorithm (Cipher)
      1. A class of cipher that uses identical keys for encryption and decryption.
      2. A symmetric key may be referred to as:
         1. secret key
         2. private key
         3. shared key
   2. Examples
      1. DES (Data Encryption Standard)
      2. 3DES (Triple Data Encryption Standard)
      3. RC (Rivest Cipher)
      4. AES (Advanced Encryption Standard)
2. Asymmetric Key Algorithms
   1. Asymmetric Key Algorithm:
      1. A type of cipher that uses a pair of different keys to encrypt and decrypt data.
   2. An asymmetric encryption algorithm uses a pair of keys:
      1. Public Key:
         1. Encrypts Data
      2. Private Key:
         1. Decrypts Data
   3. Examples of asymmetric encryption algorithms include:
      1. RSA:
         1. Named after Rivest, Shamir, and Adleman, who created the algorithm.
         2. The primary use of this asymmetric algorithm today is authentication.
         3. RSA is also known as public key cryptography standard (PKCS) #1.
         4. The key length may be from 512 to 2048, and a minimum size for good security is at least 1024. Regarding security, bigger is better.
      2. DH:
         1. The Diffie-Hellman key exchange protocol is an asymmetric algorithm that allows two devices to negotiate and establish shared secret keying material (keys) over an untrusted network.
         2. Although the algorithm itself is asymmetric, the keys generated by the exchange are symmetric keys that can then be used with symmetric algorithms such as Triple Digital Encryption Standard (3DES) and Advanced Encryption Standard (AES).
      3. El-Gamal:
         1. This asymmetric encryption system is based on the DH exchange.
      4. DSA:
         1. The Digital Signature Algorithm was developed by the U.S. National Security Agency.
      5. ECC:
         1. Elliptic Curve Cryptography is a public-key cryptography based on the algebraic structure of elliptic curves over finite fields.