Which of the following are important characteristics of VPNs? Each correct answer represents a complete solution. Choose all that apply.

A.
Authentication

B.
Encryption

C.
Data integrity

D.
Encapsulation

Explanation:
The four major characteristics of VPNs are as follows:
1.Encryption: In cryptography, encryption is the process of transforming information (referred to as plaintext) using an algorithm (called cipher) to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information (in cryptography, referred to as ciphertext). Encryption is also used to protect data in transit, for
example data being transferred via networks (e.g. the Internet, e-commerce), mobile telephones, wireless microphones, wireless intercom systems.
2.Encapsulation: Encapsulation is the inclusion of one data structure within another structure so that the first data structure is hidden for the time being. 3.Data integrity: Data integrity is a mechanism that ensures that the data is not modified during transmission from source to destination. This means that the data received at the destination should be exactly the same as that sent from the source.
4.Authentication: Authentication is the act of establishing or confirming something (or someone) as authentic, that is, that claims made by or about the subject are true (“authentification” is a variant of this word). This might involve confirming the identity of a person, tracing the origins of an artifact, ensuring that a product is what its packaging and labeling claims to be, or assuring that a computer program is a trusted one. Authentication is a process of verifying the user. The accuracy of the authentication can be determined by the number of factors used for the authentication, such as the following:
One-factor authentication
Two-factor authentication
Three-factor authentication
Multi-factor authentication
There are two authentication methods: Open System Authentication and Shared Key Authentication.
What is Open System Authentication?
Open System Authentication (OSA) is a process by which a computer can gain access to a wireless network that uses the Wired Equivalent Privacy (WEP) protocol. For OSA to work, the service set identifier (SSID) of the computer should match the SSID of the wireless access point. The process occurs in three steps:
1.First, the computer sends a request for authentication to the access point.
2.The AP authenticates the computer.
3.Finally, the computer accepts the authentication code and becomes part of the network as long as the session continues and the computer remains within range of the original access point.

What is Shared Key Authentication?
Shared Key Authentication (SKA) is a process by which a computer can gain access to a wireless network that uses the Wired Equivalent Privacy (WEP) protocol. With SKA, a computer equipped with a wireless modem can fully access any WEP network and exchange encrypted or unencrypted data.