Choose any topic from the "Key Terms" list and state the key term or concept you selected and provide an explanation on how it fits into the overall Access Control concept.

Key Terms and Concepts

Public-key Infrastructure (PKI)	Pretty Good Privacy (PGP)
Privacy Enhanced Mail (PEM)	Registration authority (RA)
Digital Signature Standard (DSS)	Digital signatures
Distinguished name (DN)	Encapsulating security payload (ESP) protocol
Encipher	Encryption
Hash algorithms	Hash functions
Internet Protocol Security	Nonrepudiation
Advanced Encryption Standard (AES)	Asymmetric encryption (public-key encryption)
Certificate authority (CA)	Cipher or cryptosystem
Ciphertext or cryptogram	Cryptography
Data Encryption Standard (DES)	Decipher
Decryption	Key or cryptovariable
Access control	Accountability (auditability)
Address restrictions	Authentication
Authorization	Discretionary access controls (DACs)
Firewall	Identification
Kerberos	Mandatory access controls (MACs)
Nondiscretionary controls	Packet-filtering firewall (filtering firewall)
Passphrase	Password
Remote Authentication Dial-In User Service (RADIUS)	Reverse firewalls
Screened subnet	Secure VPNs
Smart card	Stateful inspection firewalls (stateful firewalls)
Strong authentication	Synchronous tokens
Terminal Access Controller Access Control System (TACACS)	Trusted network
Virtual private network (VPN)	Untrusted network