Security Wireless Transmission - Vivotek IP Surveillance Overview

Chap.4 IP Network
IPSec
IPSec (IP Security) is a security protocol designed to protect communications over the Internet. Incorporating
security protocols in IP architecture can ensure network communications security, even if the data is not encrypted
with SSL/TLS.
IPSec provides two functions, authentication and confidentiality. The authentication function confirms the identity
of the source and the destination PCs so as to protect data transmitting between them. The confidentiality function
encrypts the content to prevent from interception by the third party. Both authentication and confidentiality operate
on the basis of encryption (or hashing). IPSec also provides regulations on key exchange to help generate and
manage keys for encryption.
IPSec creates a secure network communications tunnel, such as VPN (Virtual Private Network). VPN builds
transmission tunnels between two nodes on the Internet, rather than using physical cables for data transmission.

4.6.4 Security Wireless Transmission

WEP
WEP (Wired Equivalent Privacy), also known as Wireless Equivalent Privacy, is designed to protect data on a
wireless network because data transmitted by radio wave can be easily intercepted. A key must be set in the
wireless access point and when a user connects to the access point, he has to enter the same key to connect to
the Internet. WEP can provide a security level comparable to cable networks.
WEP encrypts data from wireless access points with a shared key that contains 40 to 256 bits. The longer the key,
the more difficult it is to crack, and the higher security it offers.
WPA
With the increasing computing capability of a PC, WEP, which uses a fixed encryption key, becomes vulnerable to
be attacked. Hence, the Wi-Fi Alliance developed WPA (Wi-Fi Protected Access) /WPA2 standard based on WEP.
WPA uses TKIP (Temporal Key Integrity Protocol) that dynamically changes the key for each packet during
transmission. With a 128-bit key, WPA offers a higher level of security than WEP. WPA provides data protection
via user authentication, encryption and packet inspection. It also improves wireless network management. WPA2
indicates compliance with an advanced protocol that implements the full standard. In addition, WPA defines the use
of AES (Advanced Encryption Standard) as an additional replacement for WEP encryption.
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IPSec
Network Device
Figure 4.9 Encryption of transmission tunnels with IPSec
Figure 4.10 Encryption of data with WEP/WPA
Intercepted PC
Destination PC