1. Network and Internet Security
Wireless Network Security

2. Wireless Network Security
IEEE is a standard for wireless LANs. Interoperable standards compliant implementations are referred to as Wi-Fi
IEEE i specifies security standards for IEEE LANs, including authentication, data integrity, data confidentiality, and key management. Interoperable implementations are also referred to as Wi- Fi Protected Access (WPA)
The Wireless Application Protocol (WAP) is a standard to provide mobile users of wireless phones and other wireless terminals access to telephony and information services, including the Internet and the Web
WAP security is primarily provided by the Wireless Transport Layer Security (WTLS), which provides security services between the mobile device and the WAP gateway to the Internet
There are several approaches to WAP end-to-end security. One notable
approach assumes that the mobile device implements TLS over TCP/IP and the wireless network supports transfer of IP packets
Hi-Fi (High Fidelity)

3. IEEE
IEEE 802 is a committee that has developed standards for a wide range of local area networks (LANs)
A new working group was formed IEEE , with a charter to develop a protocol and transmission specifications for wireless LANs (WLANs).
Wireless Ethernet Compatibility Alliance (WECA) later renamed as Wi-Fi (Wireless Fidelity) Alliance certifies interoperability for b products
The Wi-Fi Alliance is concerned with a range of market areas for WLANs, including enterprise, home, and hot spots
the Wi-Fi Alliance has developed certification procedures for IEEE security standards, referred to as Wi-Fi Protected Access (WPA)
The most recent version of WPA, known as WPA2, incorporates all of the features of the IEEE i WLAN security specification

4. IEEE 802.11 Protocol Stack Physical Layer Medium Access Control
Includes such functions as encoding/decoding of signals and bit transmission/reception
Includes a specification of the transmission medium
Defines frequency bands and antenna characteristics
Medium Access Control
On transmission, assemble data into a frame, known as a MAC protocol data unit (MPDU) with address and error-detection fields.
On reception, disassemble frame, and perform address recognition and error detection
Govern access to the LAN transmission medium

5. IEEE 802.11 Protocol Stack Logical Link Control
Responsible not only for detecting errors using the CRC
Recovering errors by retransmitting damaged frames

6. IEEE 802.11 Extended Service Set

7. IEEE 208.11 Services Distribution of message within DS
Integration
Association related services
Association
Reassociation
Diassociation
No Transition
BSS transition
ESS transition

8. IEEE 208.11i Wireless LAN Security
Characteristics of wired LAN that are not inherent in a wireless LAN
To transmit over a wired LAN, a station must be physically connected to the LAN. With a wireless LAN, any station within radio range of the other devices on the LAN can transmit [Authentication]
In order to receive a transmission from a station that is part of a wired LAN, the receiving station also must be attached to the wired LAN [privacy]
The original specification included a set of security features for privacy an authentication that were quite weak
For privacy, defined the Wired Equivalent Privacy (WEP) algorithm
The Wi-Fi Alliance promulgated Wi-Fi Protected Access (WPA) as a Wi-Fi standard
The final form of the i standard is referred to as Robust Security Network (RSN)

9. IEEE i Services
Authentication: A protocol is used to define an exchange between a user and an AS that provides mutual authentication and generates temporary keys to be used between the client and the AP over the wireless link
Access control: This function enforces the use of the authentication function, routes the messages properly, and facilitates key exchange. It can work with a variety of authentication protocols.
Privacy with message integrity: MAC-level data (e.g., an LLC PDU) are encrypted along with a message integrity code that ensures that the data have not been altered.

10. IEEE 802.11i Phases of Operation
Two wireless stations in the same BSS communicating via the access point (AP) for that BSS.
Two wireless stations (STAs) in the same ad hoc IBSS communicating directly with each other.
Two wireless stations in different BSSs communicating via their respective APs across a distribution system.
A wireless station communicating with an end station on a wired network via its AP and the distribution system.

11. IEEE 802.11i Phases of Operation

12. Wireless Application Protocol (WAP)
A universal, open standard developed by the WAP Forum to provide mobile users of wireless phones and other wireless terminals
WAP is designed to work with all wireless network technologies (e.g., GSM,CDMA and TDMA)
WAP is based on existing Internet standards, such as IP, XML, HTML and HTTP
The WAP specification
A programming model based on the WWW Programming Model
A markup language, the Wireless Markup Language, adhering to XML
A specification of a small browser suitable for a mobile, wireless terminal
A lightweight communications protocol stack
A framework for wireless telephony applications (WTAs)

13. WAP Insfrustucture
The WAP architecture is designed to cope with the two principal limitations of
wireless Web access:
the limitations of the mobile node (small screen size, limited input capability) and
the low data rates of wireless digital networks. Even with the introduction of 3G wireless networks, which provide broadband data rates, the small hand-held mobile nodes continue to have limited input and display capabilities. Thus,WAP or a similar capability will be needed for the indefinite future.

14. Wireless Transport Layer Security
Provides security services between the mobile device (client) and the WAP gateway
Based on the industry-standard Transport Layer Security (TLS) Protocol, which is a refinement of the Secure Sockets Layer (SSL) protocol
To provide end-to end security
WTLS is used between the client and the gateway
TLS is used between the gateway and the target server
WAP systems translate between WTLS and TLS within the WAP gateway

15. Wireless Transport Layer Security
WTLS provides the following features
Data integrity: Uses message authentication to ensure that data sent between the client and the gateway are not modified.
Privacy: Uses encryption to ensure that the data cannot be read by a third party.
Authentication: Uses digital certificates to authenticate the two parties.
Denial-of-service protection: Detects and rejects messages that are replayed or not successfully verified.

16. Wireless Transport Layer Security
WTLS Sessions and Connections
Secure connection:
A connection is a transport (in the OSI layering model definition) that provides a suitable type of service
For SSL, such connections are peer-to-peer relationships
The connections are transient
Every connection is associated with one session
Secure Session
An SSL session is an association between a client and a server
Sessions are created by the Handshake Protocol
Sessions define a set of cryptographic security parameters, which can be shared among multiple connections
Sessions are used to avoid the expensive negotiation of new security parameters for each connection
Between any pair of parties (applications such as HTTP on client and server), there may be multiple secure connections.
In theory, there may also be multiple simultaneous sessions between parties, but this feature is not used in practice.

17. Wireless Markup Language
Text and image support:
Formatting and layout commands are provided for text and limited image capability.
Deck/card organizational metaphor:
A card specifies one or more units of interaction (a menu, a screen of text, or a text-entry field).
A WML deck is similar to an HTML page in that it is identified by a Web address (URL) and is the unit of content transmission
Support for navigation among cards and deck
WML includes provisions for event handling, which is used for navigation or executing scripts

18. Reference books
Cryptography and Network Security Principles and Practices
William Stallings
Network Security PRIVATE Communication in a PUBLIC World
Chalie Kaufman, Radia Perlman, Mike Speciner