Which of the following protocols is used to provide on-demand authentication within an ongoing data transmission?
A.
LEAP
B.
EAP
C.
PPTP
D.
CHAP
Explanation:
The Challenge Handshake Authentication Protocol (CHAP) is used to provide on-demand authentication within an ongoing data transmission. Challenge Handshake Authentication Protocol (CHAP) is an authentication protocol that uses a secure form of encrypted authentication. Using CHAP, network dial-up connections are able to securely connect to almost all PPP servers. Answer option A is incorrect. LEAP (Lightweight Extensible Authentication Protocol) is a proprietary wireless LAN authentication method developed by Cisco Systems. Important features of LEAP are dynamic WEP keys and mutual authentication between a wireless client and a RADIUS server. LEAP allows clients to re-authenticate frequently. The clients get a new WEP key upon each successful authentication. Answer option C is incorrect. Point-to-Point Tunneling Protocol (PPTP) is a remote access protocol. It is an extension of the Point-to-Point Protocol (PPP). PPTP is used to securely connect to a private network by a remote client using a public data network, such as the Internet Virtual private networks (VPNs) use the tunneling protocol to enable remote users to access corporate networks securely across the Internet. PPTP supports encapsulation of encrypted packets in secure wrappers that can be transmitted over a TCP/IP connection. Answer option B is incorrect. Extensible Authentication Protocol (EAP) is an authentication protocol that provides support for a wide range of authentication methods, such as smart cards, certificates, one-time passwords, public keys, etc. It is an extension to Point-to-Point Protocol (PPP), which allows the application of arbitrary authentication mechanisms for the validation of a PPP connection.