Ch 04 wireless security

Network Security
Er. Hari K.C.
Asst. Professor
Soch College of IT
Tribhuvan University
harikc@wrc.edu.np
1
Soch college of IT - Hari K.C.

Ch 04: Wireless Network
Security

Wireless Security
• Wireless security is protecting computers, smartphones, tablets, laptops and
other portable devices along with the networks they are connected to, from
threats and vulnerabilities associated with wireless computing.
• Wireless communication refers to any type of data exchange between the parties
that is performed wirelessly (over the air).
• This definition is extremely wide, since it may correspond to many types of
wireless technologies, like :
-Wi-Fi Network Communication
-Bluetooth Communication
-Satellite Communication
-Mobile Communication
• All the technologies mentioned above use different communication architecture,
however they all share the same "Wireless Medium" capability.

Wi-Fi
• Wireless Fidelity (Wi-Fi) refers to wireless local area network, as we
all know them.
• It is based on IEEE 802.11 standard. Wi-Fi is a type of wireless
network you meet almost everywhere, at your home, workplace, in
hotels, restaurants and even in taxis, trains or planes.
• These 802.11 communication standards operate on either 2.4 GHz or
5 GHz ISM radio bands.
• These devices are easily available in the shops that are compatible
with Wi-Fi standard, they have following image visible on the device
itself. I bet you have seen it hundreds of times in various shops or
other public places!

• Due to the fact, that 802.11 based wireless network are so heavily used in
all types of environments
• They are also the biggest subject for various security researches across
other 802.11 standards.
• Wireless clients are considered to be any end-devices with a wireless card
or wireless adapter installed.
• Now, in this 21st century, those devices can be almost anything :
Modern Smartphones − These are one of the most universally used wireless
devices you see in the market. They support multiple wireless standards on
one box, for example, Bluetooth, Wi-Fi, GSM.
Laptops − These are a type of device which we all use every single day!
Smartwatch − An example of Sony based smartwatch is shown here. It can
synchronize with your smartphone via a Bluetooth.
Smart-home Equipment − With the current progress of the technology,
smart-home equipment might be for example a freezer that you can control
over Wi-Fi or a temperature controller.

• Access Point (AP) is the central node in 802.11 wireless
implementations.
• It is the interface between wired and wireless network, that all the
wireless clients associate to and exchange data with.
• For a home environment, most often you have a router, a switch, and
an AP embedded in one box, making it really usable for this purpose.

Base Transceiver Station
• Base Transceiver Station (BTS) is the equivalent of an Access Point
from 802.11 world, but used by mobile operators to provide a signal
coverage, example. 3G, GSM etc.

• In corporate wireless implementation, the number of Access Points is often counted in hundreds or
thousands of units.
• It would not be administratively possible to manage all the AP's and their configuration (channel
assignments, optimal output power, roaming configuration, creation of SSID on each and every AP, etc.)
separately.
• This is the situation, where the concept of wireless controller comes into play. It is the "Mastermind" behind
all the wireless network operation.

• SSID directly identifies the wireless WLAN itself. In order to connect to
Wireless LAN, the wireless client needs to send the same exact SSID in
the association frame as the SSID name, preconfigured on the AP.

• A cell is basically a geographical region covered by the AP's or BTS's
antenna (transmitter). In the following image, a cell is marked with a
yellow line.
• Wireless Networks may be configured to support multiple 802.11
standards. Some of them operate on the 2.4GHz band (example are:
802.11b/g/n) and other ones on the 5GHz band (example:
802.11a/n/ac).
• Depending on the band, there is a predefined set of sub-bands
defined for each channel.

• Antennas are used to "translate" information flowing as an electrical
signal inside the cable and into the electromagnetic field, which is
used to transmit the frame over a wireless medium.
• Every wireless device (either AP or any type of wireless client device)
has an antenna that includes a transmitter and the receiver module.
It can be external and visible to everyone around or built-in, as most
of the laptops or smartphones nowadays have.

Wireless networks and standards
• Wireless network may be classified into different categories based on
the range of operation they offer.
• The most common classification scheme divides the wireless
networks into four categories listed in the table below, together with
short examples.

• Since the beginning of IEEE 802.11 standard, the wireless networks
were evolving at a significant pace.
• People saw the potential in this type of data transmission, therefore
802.11 successors were showing up, few years after each other.
• The following table summarizes the current 802.11 standards that are
used in our times −

Mobile device security
• Mobile Device Security refers to the measures designed to protect
sensitive information stored on and transmitted by laptops, smartphones,
tablets, wearables, and other portable devices.
• In the age of mobile computing, the security of mobile devices is essential
and increasingly in demand because personal data and business
information are now stored and access from smartphones.
• Devices like smartphones, tablets, phablets, PDAs, and other such devices
come under mobile devices.
• Most users and businesses seek to help them communicate, organize,
manage their work and private life.
• By 2022, there will be more than 6 billion users worldwide who will be
using smartphones.

• At the root of mobile device security is the goal of keeping
unauthorized users from accessing the enterprise network. It is one
aspect of a complete enterprise security plan.
• With more than half of business PCs now mobile, portable devices
present distinct challenges to network security, which must account
for all of the locations and uses that employees require of the
company network.
• Potential threats to devices include malicious mobile apps, phishing
scams, data leakage, spyware, and unsecure Wi-Fi networks.
• On top of that, enterprises have to account for the possibility of an
employee losing a mobile device or the device being stolen.
• To avoid a security breach, companies should take clear, preventative
steps to reduce the risk.

Mobile device Threats
• As a security specialist, it is essential to know about the types of malware associated
with mobile devices.
• Mobile spyware: Spyware is malicious software that can creep into apparently
compassionate programs and, in secret, monitor your activity, track your geo-location, as
well as steal sensitive passwords.
• Mobile banking Trojans: These are mobile banking viruses that target and steal your
bank details. In the year 2017, mobile banking Trojans hit around 260,000 users across
160+ countries. They acted as if they are legitimate bank applications and then stolen all
users' bank and account details.
• Rooting malware: These types of malware try to gain root access to any mobile devices
for providing its creators or cybercriminals the administrative privileges as well as access
to that victim's files.
• SMS malware: These are used to manipulate mobile phones in sending premium-rated
SMSs, texts without letting the user know about them, and in the month-end, a large bill
comes up to that target user.

Benefits of mobile device security
Mobile device security, or mobile device management, provides the
following:
• Regulatory compliance
• Security policy enforcement
• Support of “bring your own device” (BYOD)
• Remote control of device updates
• Application control
• Automated device registration
• Data backup

Types of mobile device security
• Enterprise Mobile Management platform: In addition to setting up
internal device policies that protect against unauthorized access, it’s
equally important to have an Enterprise Mobile Management (EMM)
platform that enables IT to gather real-time insights to catch potential
threats.
• Email security: Email is the most popular way for hackers to spread
ransomware and other malware. To combat such attacks, it’s critical for
businesses to be armed with advanced email security that can detect,
block, and address threats faster; prevent any data loss; and protect
important information in transit with end-to-end encryption.
• Endpoint protection: This approach protects enterprise networks that are
remotely accessed by mobile devices. Endpoint security protects
companies by ensuring that portable devices follow security standards and
by quickly alerting security teams of detected threats before they can do
damage. Endpoint protection also allows IT administrators to monitor
operation functions and data backup strategies.

• VPN: A virtual private network, or VPN, extends a private network
across a public network. This enables users to send and receive data
across shared or public networks as if their computing devices were
directly connected to the private network. VPNs’ encryption
technology allows remote users and branch offices to securely access
corporate applications and resources.
• Secure web gateway: A secure web gateway protects against online
security threats by enforcing company security policies and defending
against phishing and malware in real-time. This is especially important
for cloud security as this type of protection can identify an attack on
one location and immediately stop it at other branches.
• Cloud access security broker: A cloud access security broker (CASB) is
a tool that sits between cloud service consumers and cloud service
providers to enforce security, compliance, and governance policies for
cloud applications. CASBs help organizations extend the security
controls of their on-premises infrastructure to the cloud.

Working of Mobile device security
• Mobile device security protects an enterprise from unknown or
malicious outsiders being able to access sensitive company data.
• Securing mobile devices requires a multi-layered approach and
investment in enterprise solutions.
• While there are key elements to mobile device security, each
organization needs to find what best fits its network.
• Here are some mobile security best practices:

1. Establish, share, and enforce clear policies and
processes
• Mobile device rules are only as effective as a company’s ability to
properly communicate those policies to employees. Mobile device
security should include clear rules about:
• What devices can be used
• Allowed OS levels
• What the company can and cannot access on a personal phone
• Whether IT can remote wipe a device
• Password requirements and frequency for updating passwords

2. Password protection
• One of the most basic ways to prevent unauthorized access to a
mobile device is to create a strong password, and yet weak passwords
are still a persistent problem that contribute to the majority of data
hacks.
• Another common security problem is workers using the same
password for their mobile device, email, and every work-related
account.
• It is critical that employees create strong, unique passwords (of at
least eight characters) and create different passwords for different
accounts.

3. Leverage biometrics
• Instead of relying on traditional methods of mobile access security,
such as passwords, some companies are looking to biometrics as a
safer alternative.
• Biometric authentication is when a computer uses measurable
biological characteristics, such as face, fingerprint, voice, or iris
recognition for identification and access.
• Multiple biometric authentication methods are now available on
smartphones and are easy for workers to set up and use.

4. Avoid public Wi-Fi
• A mobile device is only as secure as the network through which it
transmits data.
• Companies need to educate employees about the dangers of using
public Wi-Fi networks, which are vulnerable to attacks from hackers
who can easily breach a device, access the network, and steal data.
• The best defense is to encourage smart user behavior and prohibit
the use of open Wi-Fi networks, no matter the convenience.

5. Beware of apps
• Malicious apps are some of the fastest growing threats to mobile
devices.
• When an employee unknowingly downloads one, either for work or
personal reasons, it provides unauthorized access to the company’s
network and data.
• To combat this rising threat, companies have two options: instruct
employees about the dangers of downloading unapproved apps, or
ban employees from downloading certain apps on their phones
altogether.

6. Mobile device encryption:
• Most mobile devices are bundled with a built-in encryption feature.
Users need to locate this feature on their device and enter a
password to encrypt their device.
• With this method, data is converted into a code that can only be
accessed by authorized users.
• This is important in case of theft, and it prevents unauthorized access

IEEE 802.11 Wireless LAN Overview
1. The Wi-Fi Alliance
2. IEEE 802 Protocol Architecture
3. IEEE 802.11 Network Components and Architectural Model
4. IEEE 802.11 Service

The Wi-Fi Alliance
• Wi-Fi Alliance drives global Wi-Fi adoption and evolution through thought
leadership, spectrum advocacy, and industry-wide collaboration.
• IEEE - Institute of Electrical and Electronics Engineers
• IEEE 802 - Committee - LAN
• IEEE 802.11 - Committee - WLAN
• Develop a protocols and transmission specifications for WLANs
• WECA - Wireless Ethernet Compatibility Alliance industry consortium
formed in 1999
-> to assist interoperability of products
- > to concern with large range of WLAN markets including
enterprize, home and hot spots.

2. IEEE 802 Protocol Architecture

Medium access control layer and Logical link
control layer

MPDU frame format
• Media acces control layer convert data from MDSU to MPDU
• MSDU== Mac service data unit
• MPDU== Mac protocol data unit

IEEE 802.11 Network Components and
Architectural Model

• BSS - Basic Service Set
• DS - Distribution System
• AP - Access Point
• IBSS - Independent BSS
• ESS - Extended Service Set

• Basic service set (BSS)
• The smallest building block of a wireless LAN, which consists of
wireless stations executing the same MAC protocol and competing for
access to the same shared wireless medium.
• A BSS may be isolated, or it may connect to a backbone Distribution
system (DS) through an access point (AP).
• The AP functions as a bridge and a relay point.
• When all the stations in the BSS are mobile stations that
communicate directly with one another (not using an AP), the BSS is
called an independent BSS (IBSS). An IBSS is typically an ad hoc
network.

• The Services that needs to be provided by the wireless LAN to achieve
the functionality equivalent to that which is inherent to wired LAN.
• Categorization of Service:
Service Based on Provider
• DS - Distribution System
• SS - Service Station
Based on the Nature of Service
• LAN Access
• MSDU Delivery

802.11 i Wireless LAN security

802.11 i RSN services and Protocols

802.11 i Discovery and Authentication phases

802.1 X access control approach

802.11 i protected data transfer phase

Wireless Application Protocol (WAP)

WAE – WIRELESS APPLICATION ENVIRONMENT
• The Wireless Application Environment (WAE) defines the following functions:
• Wireless Markup Language (WML).
• WML is an XML-based markup language for the visual display of WAP-based
contents. Once HTML and WML will converge into XML, many compatibility
problems, during conversion from HTML to WML, will cease to exist.
• WML Script.
• A script language, very similar to JavaScript.
•
• Wireless Telephony Application (WTA, WTAI).
• Telephony services and Programming interfaces.
•
• Content formats.
• These are specifications for data formats, including images, telephone
directories, calendar information, and so on.
• The WAE corresponds to the application layer in the OSI model.

WSP – WIRELESS SESSION PROTOCOL
• The Wireless Session Protocol (WSP) implements an interface for
connection-oriented and connectionless session services. The
connection-oriented session service operates using the protocol of the
transaction layer. However, the connectionless session service uses a
secure or non-secure datagram service.
• WSP offers the following basic functions:
- Functions and semantics of HTTP/1.1, using a compact coding scheme
- Pausing and resuming sessions
- A general facility for reliable and unreliable data push
- Negotiation of protocol functions

WTP – WIRELESS TRANSACTION PROTOCOL
• The Wireless Transaction Protocol (WTP) is a transaction-oriented
protocol, executed using a datagram service. WTP offers the following
functions:
• Three classes of transaction services
(a) Unreliable one-way requests
(b) Reliable one-way requests
(c) Reliable two-way request/response transactions
• Optional user-to-user reliability feature.
• The WTP user triggers confirmation for each received message.
• Optional out-of-band data for confirmations.
• Protocol Data Unit (PDU) chaining and delayed confirmation.
• In order to reduce the number of sent messages

WTLS – WIRELESS TRANSACTION LAYER
SECURITY
• The WTLS layer implements a security protocol based on the TLS (Transport Layer
Security) industry standard. WTLS is intended for use with the WAP transport protocols
and has the following features:
• Data integrity – WTLS ensures that the data sent between the terminal and an
application server is in no way altered or damaged.
• Confidentiality – WTLS ensures that the data sent between the terminal and an
application server remains confidential and cannot be understood by any other
participant who may have intercepted the data stream.
• Authentication – WTLS ensures the authenticity of the terminal and of the application
server.
• Denial-of-service protection – Wireless Transaction Layer Security (WTLS) contains
features that will recognize and reject data that has been repeated or not verified
successfully. WTLS hinders many typical denial-of-service attacks and protects the
upper protocol layers. Though, this is not a perfect solution.

WDP – WIRELESS DATAGRAM PROTOCOL
• The WDP layer operates on various bearers that depend on the used
network type.
• WDP offers a consistent interface for the upper layers, so that
• communications occurs transparently using one of the available
bearer services.
• Therefore, the transport layer is adapted to the specific functions of
the underlying bearer.

BEARER
• The bearers that are used by the WAP protocol stack form the lower
interface of the datagram service and allow the WAP to be used for
various network types with specific bearer functions. Thus, WDP is
defined for a variety of bearers. For an IP bearer, the transport protocol
(WDP) is implemented by User Datagram Protocol (UDP).
WCMP – WIRELESS CONTROL MESSAGE PROTOCOL
• The Wireless Control Message Protocol defines the error reporting
mechanism for WDP datagrams as well as the protocol elements that can
be used for diagnosis and informational purposes (for example, WCMP
echo request and response). WCMP is determined depending on the
bearer used. In IP-based networks, WCMP functions are implemented
using the Internet Control Message Protocol (ICMP).

Ch 04 wireless security

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