-: Wireless encryption.
Another huge vulnerability in wireless networks
is the encryption that you choose to use.
In this lesson, we're going to do a quick review
of wireless encryption types
that you learned back in your Network+ studies.
The reason for this
is because encryption of your data being transmitted
is going to be paramount
to increasing the security of your wireless networks.
Now, most wireless encryption schemes rely
on a pre-shared key.
This is when the access point and the client
use the same encryption key to encrypt and decrypt the data.
The problem with this is scalability becomes difficult.
Think about it, when a friend comes over to your house,
to use your Wi-Fi,
you have to tell him your password.
Now, if you have 50 friends come over,
you're going to tell 50 different people your password,
and now, all 50 of them know your password.
And so, this is one of the first problems
that we have with wireless encryption,
is that if you're going to use a pre-shared key,
you've got to figure out a secure way
to distribute that key to everybody,
and keep it secret.
If all 50 people know your password,
then it's probably not that secret anymore.
Now, there are three main types of encryption
that are in use from wireless networks.
We have WEP, WPA, and WPA2.
WEP is our first one.
WEP is the Wired Equivalent Privacy.
This came from the original
802.11 wireless security standard,
and it claimed to be as secure as a wired network.
I'm going to prove this wrong to you,
in our demonstration later,
because we're going to brute force WEP,
and break it in about three minutes.
WEP was originally used
with a static 40-bit pre-shared encryption key,
but later it was upgraded to a 64-bit key,
and then, again, to a 128-bit key.
This isn't the main problem with WEP, though.
The main problem is a 24-bit Initialization Vector,
or IV, that it uses in establishing the connection,
and it's sent in clear text.
As I said, WEP is not very secure,
and because of this weak Initialization Vector,
we're going to be able to brute force WEP
in just a couple of minutes,
using using Aircrack-Ng and other tools.
So, to replace WEP, they came up with WPA.
WPA is the Wi-Fi Protected Access standard.
It uses a Temporal Key Integrity Protocol, or TKIP,
which uses a 48-bit Initialization Vector
instead of the 24-bit Initialization Vector used by WEP.
The encryption that it uses is the Rivest Cipher 4,
or RC4, and it added Message Integrity Checking, or MIC.
And it uses all of this
to make sure that the data is secure,
and ensuring that it's not modified in transit.
Overall, it's a pretty good standard,
but it does have some flaws,
and so version 2 was released to fix those.
WPA version 2, or Wi-Fi Protected Access version 2
was created as part of the 802.11i standard
to provide stronger encryption
and better integrity checking.
The integrity checking is conducted through CCMP,
which is the Counter Mode
with Cipher Block Chaining
Message Authentication Code Protocol.
And the encryption uses AES,
the Advanced Encryption Standard.
AES supports a 128-bit key or higher,
and WPA2 uses either a personal mode,
with pretty short keys, or an enterprise mode,
with centralized authentication via a radio server,
or another centralized server,
to handle that password distribution we were talking about.
Now, I want to pause here for a second,
and before we go any further,
give you a couple of quick exam tips.
First, if you're asked about Wi-Fi,
and it uses the word Open in the question,
it's usually looking for some kind of answer
that says the network has no security, or no protection.
If they mention WEP,
I want you to think about Initialization Vector.
If they mention WPA,
you should be thinking about RC4 and TKIP.
If they mention WPA2,
you should be thinking about AES and CCMP.
You keep those little things as study tips in your mind,
you're going to do well on the wireless encryption questions.
Now, there's a couple other things to mention
in regards to wireless encryption.
One goes back to my old favorite saying,
if we make operations easier, then security is reduced.
And, that's exactly what happened with WPS.
WPS is the Wi-Fi Protected Setup, which was designed
to make setting up new wireless devices easier.
For example, if you have a new printer
you want to configure,
you'd push a button on your wireless access point,
you'd push a button on the printer,
and you'd enter a PIN number, and boom,
those devices would do a handshake,
they would pass over the secret credentials,
and both would now be encrypted.
This is great, but, it was horribly executed.
WPS relies on an eight-digit code,
but when they sent that code,
they actually break it up into two four-digit chunks.
This takes something that would have been eight-digits long,
and, essentially, makes it four-digits long.
And that makes it a lot easier to brute force,
because each four-digit chunk only has
10,000 possible combinations.
Your computer and my computer
can go through 10,000 combination pretty darn quickly,
and brute force that password.
Now, in my Wi-Fi hacking course,
I actually show you how to break WPS,
and how to break through all these different networks,
but for the Security+, what you need to know
is that WPS is bad, it's vulnerable,
and it should be disabled
on all of your wireless access points.
Finally, in addition to using the WPA2 standard
for your encryption,
you should also set up a VPN for your wireless devices.
Anytime you connect to a Wi-Fi, even your own,
you should always use a VPN
to protect the data that's going across it.
Never, never, never, never, never trust a wireless network.
If you use one, you should always have a VPN.
This is an encrypted tunnel
inside of this encrypted wireless tunnel
that adds security.
Trust me, encryption and VPNs are your friend
on the Security+ exam.
They're almost never the wrong answer.
Those two things come up time and time again.
Remember, you can have an encrypted WPA2 tunnel,
and then put a VPN encrypted inside of it.
That gives you two layers of encryption
and makes your wireless networks much, much more secure.