WEBVTT

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 Welcome to this video where we're continuing
 our refresher and review

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 of Wi-Fi topics.

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 So now we're going to get
 into Wi-Fi authentication.

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 We're going to do a brief overview
 of what authentication is and some

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 very high level differences
 of Wi-Fi authentication.

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 Okay. So, security with wireless LANs,
 the objective is very similar to

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 the security on wired LANs.

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 So there are three things that ideally
 we'd like to accomplish.

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 Authentication, make sure that only authorized
 users can access our wireless

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 LAN. Data confidentiality, make sure
 that people who might be able to

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 sniff our traffic
 can't decrypt it.

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 They can't see what's in there.

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 It's useless to them.

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 And data integrity, make sure that
 nobody can change our data as it's

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 going across the wireless LAN.

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 All three of these steps are typically
 accomplished after you've already

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 associated to your SSID.

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 And authentication can occur independently
 of encryption or integrity.

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 So, let's do a quick review here of
 what's involved when you're actually

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 associating to a wireless LAN.

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 So in the world of the 802.11, the IEEE's
 802.11 standard for Wi-Fi, not

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 only does your Wi-Fi data go across the
 radio waves, but there are certain

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 802.11 frame types are used to control
 access to the Wi-Fi medium, who

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 can talk authentication.

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 And so we need to also know what some
 of these messages are, not all of

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 them. So number one, the client discovers
 the wireless LAN, typically

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 done because you've received a beacon
 frame from the access point.

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 So now you know the MAC address of the
 beak of the access point, and you

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 know the name of the SSID that the access
 point is advertising, like in

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 this case that SSID is corporate.

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 Also within that beacon, the access point
 will indicate what type of authentication

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 and security it's doing.

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 Like it says right there.

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 Now, the in the beacon authentication
 is going to be advertised as one

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 of two types, either pre-shared
 key or open authentication.

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 You will not see pre
-shared key anymore.

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 That was something that was in the very,
 very early days, you know, the

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 mid 90s of 802.11 wireless LANs,
 but that is no longer there.

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 So now we use open authentication.


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 Next, there's going to be exchange of
 another kind of a frame in 802.11

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 frame type, which is called authentication
 request and authentication

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 response frames.

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 So with open authentication, so back
 in the days of pre-shared key, your

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 authentication request would actually
 have a pre-shared key in it.

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 It would have to password.

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 You would send that in your authentication
 request, and then the authentication

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 request would say, you're in, you're
 good, or nope, you didn't supply

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 the correct password.

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 The problem was there were a
 lot of ways to crack that.

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 It was not very secure at all,
 so they deprecated it.

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 So open authentication, it's not
 even really authentication.

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 It just basically says, hey, can I
 come into your wireless LAN and the

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 default response will be yes, authentication
 response, you're in.

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 Now, does that mean that there's
 no exchange of passwords?

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 Well, not at this step.

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 If we're doing authentication on our
 wireless language, most wireless

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 LANs have authentication.

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 It's actually going to happen
 later on, not right here.

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 Okay, and now we're going to send association
 request and response frames.

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 So association request is basically
 the client's way of saying, hey, you

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 know, do you have room for me, or have
 you maxed out on the maximum number

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 of clients you can support, Mr.

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 Access Point? So if the Access Point
 is good to go, if it has room for

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 you, it'll send an association response
 and say, hey, you're in, and here's

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 a unique ID for you.

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 And from this point on, all of your
 frames you transmit to that Access

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 Point will have a Wi-Fi header and
 802.11 header, and somewhere within

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 that header among many other things
 will be this association ID that you

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 got from the Access Point, so it
 knows that it's talking to you.

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 Okay, so now at this point, after you've
 associated to the Access Point,

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 after you are formally a part of his
 BSS, you haven't gotten permission

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 yet to go beyond that.

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 You haven't got permission yet to go
 onto the wired LAN, or even to talk

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 to other Wi-Fi clients
 in the same BSS as you.

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 Now we need to do real authentication,
 and that takes place next.

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 So the act of authentication can be accomplished
 with or without encryption.

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 As it says, there's two ways of
 implementing authentication.

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 We could authenticate the user, which
 is a typical way, so the user would

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 have to know some sort of a password, or
 maybe even a username and a password,

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 or we could authenticate
 the device.

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 So maybe the device presents something
 like its MAC address or something,

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 which is pre-known to the wireless LAN
 controller, and so we allow that

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 device in. All right, so take a look
 at the screenshot right here.

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 We see some wireless LANs, like
 Pirates and like Bogart.

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 Wow, that one looks familiar.

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 Let's say WPA personal or WPA two personal,
 other ones that say none.

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 So if a wireless LAN says none, that means
 it's not offering you any encryption.

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 Now it doesn't mean anybody can get
 in, it just means, hey, if you get

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 access to our wireless LAN, just be
 warned that everything you send over

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 the airwaves is going
 to be unencrypted.

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 So anybody with a wireless sniffer
 can see what you're doing.

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 Now it still might use
 though authentication.

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 Now in this case, the authentication
 is probably going to be something

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 called a captive portal.

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 A captive portal, I'll show you what
 that looks like in just a moment,

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 but a captive portal is typically
 where, like in most hotels, right?

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 Most hotels like Fairfield in
 this case, Fairfield Guest.

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 So when you connect to that and you
 associate to it, the next thing that

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 happens is a web page pops up.

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 And the web page says, you know, type
 in your Fairfield credentials, like

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 your room number and your last
 name or something like that.

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 And if you type in that correct information,
 now you've been authenticated.

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 You've supplied the correct credentials
 and now you can have full access

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 to the internet at that point.

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 Now still, nothing's encrypted.

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 So all the Wi-Fi stuff you're doing
 between you and the access point,

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 wherever it is, you know, down
 the hall or up in your room.

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 There's no encryption here, but they
 did use that web page to authenticate

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 you. That's what we mean
 by a captive portal.

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 There's also other methods 802.1x and
 Mac authentication, which could

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 also be used to verify that you are who
 you say you are and yet not provide

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 you any kind of encryption
 capabilities.

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 What's another way that you can
 identify unsecured network?

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 All right, so when a network displays as
 secure, this means it is advertising

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 encryption. It means you have to be able
 to support the encryption that's

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 doing. So which is identified
 via the lock symbol.

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 So notice these two first wireless
 lands here have a little padlock.

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 That indicates that that is
 a secured wireless land.

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 Not only will it require some sort
 of authentication from you, like a

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 username and password or maybe just a
 password, it will also require that

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 you support the method of encryption
 that it uses so it can encrypt your

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 data. The one below it, for
 example, cable Wi-Fi here.

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 Notice there's no padlock there.

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 So that wireless land could
 be one of two things.

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 It could be completely open with
 no passwords or anything.

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 This gives you freedom to do wireless
 or it could use a captive portal

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 or something, which means that you would
 have to supply some sort of credentials.

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 So like, for example, if I clicked
 on cable Wi-Fi on here, instead of

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 giving me unfettered access to the
 Internet without authenticating me

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 or asking me any credentials whatsoever,
 I might see a page that looks

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 like this. You've probably seen
 this before in some environment.

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 And now I have to select one of these
 buttons, you know, do I use optimum?

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 Do I use spectrum or or XFINITY?

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 And then once I do that, they're probably
 going to have me presented with

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 another website where I'm going to provide
 like my username and password

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 for spectrum or my XFINITY account
 number, something like that.

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 So it's going to be asking me for some
 sort of authentication and then

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 I'm in. But because there was no padlock
 there to begin with, I'm not

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 going to get any kind of Wi
-Fi encryption whatsoever.

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 So we would consider that to
 be an unsecured network.

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 So that completes this video, which is
 our first preliminary introduction

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 into Wi-Fi authentication.