Some wireless networks provide a one-to-one connection
between the two devices communicating on that network.
You might use a point-to-point connection
if you're connecting two buildings together
with a wireless network, and you would
have a directional antenna that would connect from one building
to the other.
This is often used with Wi-Fi repeaters
that you might have in your home, where the repeaters are
communicating directly between each other
with a point-to-point network connection.
But it's more common to have 802.11 networks that
are communicating from point-to-multipoint.
This is probably one of the most common types
of wireless networks that we use today.
There's not necessarily full connectivity
between all of these devices.
For example, a device on one end of the network
can easily communicate to the access point,
but it may not be able to communicate directly
with devices on the other side of that access point,
because they're simply too far away.
There might also be configurations
within the access point that would allow
the devices to communicate to the access point
and then to the internet, but it may
have restrictions built into the configuration that
will prevent devices on the same wireless network
from communicating with each other.
Another popular wireless network type
is the cellular network that we use for our mobile devices,
or our cell phones.
The cellular network towers separate the network
into individual cells.
And each antenna is going to have
a different set of frequencies that are used
for each cell of the network.
There are some security concerns associated
with cellular networks.
On some cell networks, you might have the ability
to monitor the traffic that's being
sent between the mobile device and the cellular tower.
And there may be location tracking functions,
so that someone may be able to know exactly where you are
based on the signal that you're sending
to these cellular towers.
There's also access to these cellular networks
from many places around the world.
So you can take your phone with you
and be able to connect and communicate
over almost any one of these networks.
This creates concern for the security professional, who
wants to be sure that people authenticating
into their network are people who are authorized.
And if someone is communicating from a different country,
you may have to consider that when
implementing some type of access control into your network.
Unlike cellular networks, which have a larger scope,
Wi-Fi networks tend to be very local.
So any concerns we have with security
are all based on a local access point and devices
in our immediate area.
Of course, there are important security concerns
on Wi-Fi networks as well.
We want to be sure that we are encrypting all of the data
center over that network, so that no one could connect
to, and be able to see, any of the traffic
that we're sending back and forth.
We also have to be concerned about an on-path attack, where
someone can sit in the middle of a conversation
and be able to watch the communication go
back and forth.
And of course, there's always concern
that someone might interfere with the frequencies
that we're using, effectively creating a denial of service.
Bluetooth networks are commonly used
to connect our mobile devices and their accessories all
to each other.
Sometimes you'll see these Bluetooth networks referred
to as a PAN, or a Personal Area Network.
It's common to see Bluetooth functionality
in our laptops, our tablets, and our smartphones,
and we often can use Bluetooth to tether
those devices to create an internet connection where one
wouldn't commonly be available.
You'll also find a number of headsets and headphones
that can connect to our mobile devices,
and even health monitors that you might wear on your wrist.
It's common to see Bluetooth used in our cars,
so we can connect our mobile phones
into the console of our trucks and our cars,
along with the smartwatches that we might be using.
And if you have mobile speakers like these,
you can use Bluetooth to connect your mobile device
to these external speakers.
A very common wireless network type is RFID.
That stands for Radio-frequency identification,
and RFID is used in so many aspects of our lives today.
If you use an access badge to gain access
through doors at work, then you're
probably have an RFID chip inside of that badge.
If you work on an assembly line, or you
need to track where certain equipment may
be in a warehouse, then there's probably
RFID inside of that pallet, or inside of those boxes.
Many of our pets have RFID chips inside of them.
So we can track them and find them
if they happen to get lost.
Anything that needs to be tracked,
tends to have RFID connected.
Primarily because RFID is so small.
This is an RFID chip right next to a grain of rice.
You can see that you could put this RFID interface almost
anywhere.
RFID works using radar technology.
We would send a signal to this RFID device.
It is powered from that signal, charges the chip,
and then information is transmitted back
from that powered connection.
You're able to get information or an ID number from that chip
that you can then associate with where that chip happens to be.
Some RFID tag formats don't require that you power them
with the RF signal that you're sending originally.
Instead, they may be locally powered,
and they may have other methods in order
to send their ID information out over the wireless network.
A technology that builds on RFID is near field communication,
or NFC.
This is a two-way wireless communication
that is generally used with two devices that
are very close to each other.
This is commonly seen with payment systems.
So you may be checking out at the store,
and you can pay for your groceries, or other items,
using this NFC from your watch or your mobile phone.
We can also use NFC to speed up connectivity.
For example, NFC is commonly used to bootstrap the Bluetooth
pairing process.
And since this NFC device acts as a unique piece of hardware,
we could also use this as an access token
or an identity card that might gain
you access to a locked room with an NFC card reader.
The security concerns we have with NFC
are very similar to those that we
have with other wireless network technologies.
For example, it may be possible to capture
the information that's transmitted between your device
and the NFC device.
You do have to be very close to capture that information.
But since it is wireless, there is that potential.
And of course, because there are frequencies in use,
someone could jam those frequencies,
and create a denial of service situation.
If there is someone in the middle of this conversation,
they may be able to modify the information that's
being sent back and forth, effectively
creating and on-path attack.
And of course, if you lose your phone
or you lose this mobile device, you've
then lost the ability to use this NFC functionality.
And of course, you want to make sure it's
protected, since there could be financial details that are
stored and accessed using NFC.
We used to use IR, or infrared communication,
on our mobile devices.
And we tend to use much more to 802.11 and Bluetooth
these days.
But infrared is still used in many places.
Especially if you're connecting to some type of media center,
or entertainment center, and you're
able to control the devices on that entertainment center using
infrared.
For that reason, you'll still find a number of mobile devices
that have IR capabilities built into them.
If you do have two devices that can communicate via infrared,
it is possible to transfer files between those two devices.
And from a security perspective, you
have to know that infrared doesn't have a lot of security
controls built into it.
So it is possible for other devices
to be able to control your infrared devices using IR.
One of the most common wired mobile connection types
we have is USB, or Universal Serial Bus.
This is commonly how we connect to our mobile phones
to transfer data, charge the devices,
or transfer files between your computer and this device.
Some phones have USB on the phone
itself, although it could also be something proprietary,
such as a lightning connector.
Since USB is a physical connection,
you would have to be nearby to be able to connect devices
using USB.
This certainly limits access to the device,
especially if you've disabled access
over a remote connection, and required access
with a physical wired link.
Of course, you can transfer data over this USB connection.
So you want to be very careful where you're plugging in.
And if you are connecting to an unknown USB connection,
it might be a good idea to leave your device locked
so that no data can be transferred.
And if you are plugging in via USB,
you could use your phone as a mobile storage device.
This could be a concern for highly secure areas
since you don't want someone copying
information from your internal network onto your phone,
and then walking out of the building with that data.
If you've used the map functionality
on your mobile phone, then you've taken advantage of GPS,
or the Global Positioning System.
This is a technology created by the US Department of Defense,
and there are about 30 satellites in orbit
that are providing this GPS functionality.
This provides very precise location information
for your mobile device.
You would need to see at least four satellites
to be able to use this GPS capability,
so it's often easiest to use if you're near a window,
or you're outside.
GPS is able to determine where you are based on the timing
differences from each of these different satellites.
And by using these timing differences,
it can determine your latitude, your longitude,
and your altitude.
We use GPS extensively on our mobile devices,
and we commonly use it for maps and directions.
You can also use GPS in conjunction
with other types of networks as well,
to be able to triangulate where a person might be.
So your location may not only be based on GPS,
there may be Wi-Fi and cellular tower triangulation, as well.