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Wireless transmission is usually a topic that raises many concerns
in the security world. It seems common knowledge
nowadays that a wireless network can be easily hacked, and
private information can end up on the Internet or someone’s
identity can be stolen. This is a major concern at the
consumer level. When you walk into a computer store looking for the latest wireless
802.11 access point, security and encryption features are written all over the
box, and you will most likely end up buying whatever seems to have the highest
level of encryption. Most of today’s home access points have advanced encryption
systems mainly to prevent a neighbor from stealing a Wi-Fi connection.
Security and encryption becomes even more relevant in a corporate network
where even the smallest breach could lead to a major security threat and millions
of dollars in damages. Different from home networks, corporate networks get attacked
on a regular basis, so a high level of security is needed. The issue is even
more relevant for city or municipal networks since they could be controlling some
key operations that could heavily affect a city and its safety.
The issue of network safety and security is real and an important one to keep
in mind; however, the key question that needs to be asked is how network security
and encryption on wireless differs from a wired network. The truth is: It’s not very
different. Wireless networks are not necessarily less secure than wired networks.
What people don’t realize is that sometimes it is easier to tap into a switch in a
cabinet than to play around with wireless. So, let’s review some of the key things
that should be kept in mind to make a wireless network secure.
Transmission protocols. Wireless networks can be divided in two groups: ones
that use a standardized transmission protocol and ones that use a proprietary
transmission protocol. A standardized transmission protocol, for example, is
802.11, 802.15 or Zigbee. It is a protocol that follows certain characteristics to
guarantee interoperability between devices made by different manufacturers.
Standard Wi-Fi connectivity is probably the best example of this. When you go
to Starbucks and connect to the wireless network, it doesn’t matter if you are using
an Apple or a PC, an iPhone or Android, or even a Blackberry because they
all have a Wi-Fi-compatible interface that allows you to connect to the network.
This is great for public Wi-Fi and any network that
requires compatibility with multiple devices; however,
this also poses a threat when it comes to security,
as there are numerous devices that can communicate
with your network.
Consequently, if security is your main concern,
you should try to look for a wireless network that uses
a proprietary transmission protocol because this will
strongly limit the number of people who will be able
to access it.
Authenticated routing. Regardless of the type of
transmission protocol you are using, authenticated
routing will prevent other wireless devices from interacting
with your network. This is a key feature
on the majority of wireless devices, but, before committing
to any specific solution, you should know if
it offers authenticated routing and understand how
it does it.
Authenticated routing is enforced
with a passphrase that is needed for two
access points to communicate. WPA and
WPA-2 are two of the most common authentication
standards on a Wi-Fi network
and provide a reasonable level of
protection. It also is worth noting that
WEP is no longer a secure method to
prevent hackers from getting into your
network and should be avoided at all
costs. WEP can be cracked in less than
five minutes using any laptop and software
that is readily available on the web.
Control user impact. Most security
breaches are, in fact, due to lack of
knowledge on the user’s part. One of the
most common accidents is caused by the
so-called Rogue Access Point, a standard
open 802.11 AP that is wired into the
network by one of its users. This needs
to be prevented as it could jeopardize the
overall safety of the network and create a
very easy entry point for hackers.
Detecting Rogue Access Points is a
feature that is usually present on most
enterprise networks. In home or small
office networks where consumer-grade
access points are used, though, this feature
is not present, so attention should
be given to other people attaching access
points to the network.
Filter the MAC addresses. This allows
control over which devices have
access to the network, thus preventing
another unknown device from being
able to connect. This also prevents unknown
devices, such as laptops or cellphones,
from connecting to the wireless
access point and is an effective way to
keep tabs on who uses the network.
Encryption. Usually accomplished
using a built-in encryption module on
the wireless device or by adding a VPN
box to the network, the goal of encrypting
traffic is to add an additional
level of protection to the data traveling
on the network to prevent people from
being able to understand the information being transmitted.
Most devices on the market use
AES-128 bit or AES-256 bit encryption.
The AES standard is one of the
most widely adopted encryption systems
due to its high level of security.
When activating encryption, it is important
to keep in mind network performance.
Given the large amount of
data processing needed for encryption,
it’s usually recommended to use a device
with a dedicated encryption module
or a separate device to avoid creating
an overhead on the network.
Limit the range of the network. Limiting
the power output and controlling
the coverage area by using directional
antennas are very effective ways to reduce
the number of people that could
have access to the network and might
try to hack into it. More power is not
always equivalent to a better connection
due to issues such as co-location
interference that might be present in
a network with more than one access
point that are close to each other. Controlling
the output power of the access
point can be easily done through the
user interface with just a few clicks.
Wireless networks can be very secure
and reliable transmission systems
as long as certain rules are kept in mind
and adhered to. In addition to upgrading
to the latest technology and encryption
systems, employees’ knowledge
goes a long way in making any network
more secure, regardless of whether it is
wired or wireless.
This article originally appeared in the April 2014 issue of Security Today.