Hero and welcome back in today's video, we'll have a high level overview about the East GDP's protocol.
No E setpiece is basically an extension to East CDB.
Now in HD is that communication is encrypted using the transport layer.
Security, which is also referred as the else now to Alice, is basically a newer version of it.
And so you might have heard, as I said, somewhere down there, we know the protocol, the state-based
protocol is a reference to you.
So this protocol is also referred to as E CTP, Orioles or ECB or address.
Is it so many times within your browser when you open up websites like banking websites or typically
websites, which might can be more sensitive information?
You'll see this lock and also green a CDP.
So this log basically means that your communication is secure.
So this is my best website, and if you see the domain is labs internal dot com and it has this green
lock.
Right.
So this green lock and it is TDPs.
Same goes with their banking website.
Even for banking website use, it has this green lock and it has the E stubs.
So that basically means that the communication that might be happening between the claims of land can
be this browser and the website here.
In this case, it is said that communication is encrypted and that can be verified, that there's a
green lock order is within the domain.
So let's understand certain scenarios where a CD case proves to be very useful.
So in this scenario, you have a user who is sending his username and password in a plain text to the
web server for authentication.
So you have a web server, so this can be certain applications and this is they use it.
So you are one of those website from your browser and a website.
Ask you for login and password.
So you put your logging username as epilepsy and you put the password as this or didn't password know
if there is an attacker who is sitting between them.
So there is an attacker who is sitting and sniffing the network.
Then he will be able to fetch all the credentials which are passing in this network within plaintext.
So if you see earlier, you have a attacker who is doing a man in the middle attack, he fetched the
username.
You face the password and he's doing it within his database.
So the longer he snips the network, the more username and password he'll be able to get.
Now, the reason why he's able to get the password and username is because they are traveling in a plain
text.
So data it is plain text protocol like you have FPP, you have a CTP.
So if you use that plaintext protocol to transfer sensitive data, then if there is, there might be
an attacker, then your credentials would be leaked.
Now there's also a second scenario where you have a man in the middle with integrity attacks.
So what happens in the integrity attack is that attacker is changing the payment the way the packets
are in transit.
So let's see that you are sending information that send $100 to the electric bill starting so the attacker
can modify the attacker and receive it, and he can modify the details.
So it is $700 to attacker the example.
Exemplary internet so know the destination, so it will receive this details.
And if the destination.
So it's intended to alert to the attacker, then his attack is completely successful.
So this is the integrity attack, whether data itself is changed or during the transit.
So to avoid the previous two scenarios that we discussed and also various others, various cryptographic
standards were clubbed together to establish a secure communication order and trusted network and those
standards the jury clapped together when knowing it as a safe place.
So this was the initial version of the protocol, which was basically intended for secure communication.
So SSL 2.0 was released in the year 1995.
Then certain improvements.
Then you have SSL 3.0 on 1996.
Then the name got into the various protocols which are used in SSL 3.0 could be easily compromised.
So let's say that you're using a secure communication with SSL 3.0, then the protocols which were being
used because SSL and bill is just cryptographic standards.
So it in turn contains a lot of data protocols, some protocols I generally use.
Encryption, some protocols are being used for integrity in others.
So SSL 3.0, the protocols that were used here, they're deemed to be unsafe.
That means they could be compromised.
So SSL 3.0 seems to be used and you had the brand new build standards.
So to add this, the name change the overall concept remains the same year that different protocols
are being used here.
So you have to release 1.0 in 1999.
Then you have 1.1, then your 1.2, and you have the latest 1.3 in 2018, which was released.
Now let's understand it in an easy way.
So what happens here is that every website has a certificate, so every website which uses a DBS has
a certificate.
So a certificate is basically like a passport, which gets issued by a trusted entity.
So passport generally gets issued by a government, whichever government.
So in my case, if I am living in India, then the passport is issued by Government of India.
However, before passport gets issued, whatever contents are dead within that passport, so it might
be your name, your date of birth, your address, that contents will be verified by the government.
So typically in India, before the passport is issued, you'll see that the cops they visit your place
to verify whether you're actually living there and the data that you have shared is not malicious.
One.
So everything is verified within your passport and in a similar way.
This certificate is also like a passport.
It contains a lot of information, and that certificate is issued by a trusted and did so.
This certificate has a lot of details like your domain name, its validity, the public key and others.
So this is a sample certificate on how exactly it looks like.
So if you see this certificate is issued to zebra dot com similar to passports, so if I have a passport,
the passport will have a name, says Zalora.
Similarly, the certificate that is being issued for your website, it will have that domain name of
your website, which is silver dot com.
Now, along with that, it has a lot of other information like Virgin.
You have serial number, you have certificate signature algorithm, you have the issuer and also the
validity, as well as the public key related information.
Now, generally, whenever you open up a setpiece website, the web server will send you its certificate.
So that is the first thing.
So you have, let's say, the web server has sent you its own certificate.
So this is like a big certificate because it contains a lot of information.
Now the browser.
So in this case, Glenn verifies if expressed, the certificate issue or not.
So this is a big thing.
So the plan has to validate if the trust or not.
OK, now if it rests, it will also verify all the details which are within the certificate.
Like when you go international, then during the channel they will verify eaten everything.
They once it verifies and it accepts it to be genuine, then it will take the public key information
from this certificate.
So this certificate has the public key.
And then it also initiates the negotiation.
Now we know that a deal is basically used primarily for secure communication, so that is one of the
important use cases.
So in order for secure communication, it takes the public information so you'll understand the public
and private key if you know the asymmetric key encryption.
So asymmetric encryption is used to generate a new temporary symmetric gate, which will be used for
secure communication.
So what happens here?
It takes the public information and a secure password, so it's something like a secure password is
generated.
So that secure pass foot, which is rightful as a symmetric key, will be used for encrypted and decryption
related operations throughout the channel.
However, that secures the key is passed through asymmetric key encryption.
Yet so that's the high level of what are you?
Let me quickly show you a few things, so if I just open up the labs internal dot com, so this is our
test website.
So when they just open this up, it basically sees secure connection.
So let me just expand it, and it is verified by Let's Encrypt.
So that basically means that whatever details that are part of this certificate are being verified by
issuer.
In this case, the issuer is let's encrypt.
There can be multiple issuers.
So when you do a mordi information, you'll be able to get the certificates for.
Civic information, so ABC that this certificate is issued to Labs internal document, it's verified
by listing group and it expires on 24 September 2019.
Now, if you go into the technical details, it seems that the connection is encrypted and basically
these are the protocols which are being used for the auto encryption.
And yet you have list was in one point two.
So if you want to look into the actual certificate, this is how the certificate looks like.
Where you have the common name, you have this serial number, you have the begins on.
So then it was issued.
Till then it is issued.
That basically means the expiry as well as the fingerprint.
Now, if you look into the details, these are older details which are part of the certificate.
So you had the certificate version, you had the serial number, you have the issuer.
So in this case, the issuer is let's encrypt.
We already seen the validity.
Now this is one of the important part.
So this is the public key algorithm, which is odd, is it?
And this is the actual public key.
I think so.
This is the public key through which the new symmetrically is generated, which in turn would be used
for the encrypted communication.
So it's like you cannot really saying that symmetric key to what the website in plain text, if you
send it in plain text again, the attacker will be able to find that out.
So you make use of this asymmetric encryption to send the new symmetric key, which will then be used
for communication.
So what happens?
The web browser takes this public key.
Then the symmetry key is encrypted with this public key and send it over to the web server.
Now, since the web server holds the private key, it will be able to decrypt the encrypted packet and
then the communication can begin.
No one patient comes this way.
Will browser trust this?
So let the browser receives a certificate and the certificate is verified by X-Y-Z.
No viable browser trust that that is the first question.
And second question is who will browser trust and who will not trust?
So in order to understand that?
Let's go to options, will go to privacy and security, and let's go to view certificate.
So you're this basically contains the list of certificate authorities, which browser trust.
So these are the entire list of the certificate authority, which my current Firefox browser trusts.
So if you go a bit up within the trusted entities you also have, let's encrypt over here.
So this is how things look.
So generally, these issuers that you have these issuers, you will have to pay to them.
So let's open up one of them.
So one of the issuers, you have a Comodo.
So Comodo is also one of the state entities within the browser.
So if you look into the SSL certificate, you can basically produce the SSL certificate from them.
So basically, they will verify because the issuer, whoever is the issuer, has to verify the details.
So if you're going through Comodo, then you will have to verify.
Then the Comodo will verify the details here.
So let's do one thing.
Let me quickly open up Wireshark.
And let's get to the packets going from the wireless interface.
And now let's open up a new private window and open labs internal dot com.
So let's go back to Asia.
I'll stop the packet capture.
So let's do anything.
Let's quickly find out the IP address associated with the domain.
So this is the IP address and we'll quickly create a filter.
So this is a field day, so any package going from my laptop towards the destination.
So currently you see the first package was sent.
So this is part of their DCP handshake.
So as part of the deal is handshake.
You have that line.
So any client who wants to communicate via the deal's protocol, the first packet is then the lead that
line?
Hello.
So if you go bit down, you also have the client.
And so generally, we already discussed that the server would typically send the certificate, so the
certificate would have all the information, including the public key.
So once the public key is being received by the client and the symmetric key is generated, then you
have the key exchange which happens, then you have the joint cipher spec.
And this after Jeanne safer speak, you have the encrypted message.
So this is part of the protocol again will not be discussing in detail about the deal is antique as
of now.
But generally, after this encrypted handshake message, then you typically have the application data.
Now, if you look into the application data, so all the data is basically encrypted, so you will not
really know what exactly is being passed through.
So there is any attacker who is sitting in between.
He'll not be able to get what exactly is this?
And if we look into the data protocol, it is a steep old bill as this is something that we discussed
in this slide one.
To conclude this video, we just discussed the web server configuration because here when we open up
labs internal dot com, it automatically happened to be is trusted and data automatically appeared within
the browser.
But internally we saw that there was a lot of things that happens in that DNS handshake.
So within a web server configuration, also, the web server has to supply the certificate to that land.
Otherwise, how will Klein know?
So basically, so let's say this it is only this can we labs internal dot com.
So what happens here is that you have a sense of SSL and the school certificate event.
This is the certificate chain.
So this is the certificate which is being passed to the client.
So Klein will then verify this certificate contents.
And you also have the SSL certificate key.
So this is basically the private key.
So we know that within the asymmetric encryption, that is what the public and the private key.
So if a browser is encrypting the data with the public key, then the web server will be carrying that
data with the corresponding private key, which is being stored within that zip server.
So the importance of this private key would still be tremendously important because essentially, if
this private key is being stolen, then the communication can be decrypted as well.
So that's the high level.
What have you about these steps?
I hope I took.
Glad you understood the steps protocol and why exactly it is being used for.
So with this, we conclude this video.