Now that we understand how PDP works in this lecture and the next few lectures I'm gonna show you how
to use it to encrypt all kinds of data verify integrity and so on.
Now as I explained in the previous lecture for this to work the receiver which is John in this case
has to first generate a key pair a public key and a private key.
He will share the public key with the person who he wants to receive data from that person who is David.
And this example will use the public key to encrypt the message send the message to John.
The message will be unreadable unless the private key is used to decrypted.
And as you can see throughout this whole scenario the private key never left John so John never shares
the private key.
And it is the only key that can be used to decrypt the data.
Therefore this implementation is very very secure so like I said the first step for this is the receiver
needs to generate a keeper a public key and a private key.
So in this lecture I'm going to show you how we can create our own keeper so that we can share our public
key with the people that we want to receive data from.
And then they can use this public key to encrypt data and send it to us so that we are the only ones
that can decrypt this data because we have the private key so entails.
This is actually very very easy.
You can do it using the clipboard applet that we have in here on the top right.
So you can click on it and go to manage keys.
Now in the recent versions of tales they've been moving this all over the place.
So if you can't find it here we can go to applications utilities and click on passwords and keys.
This will open a program that can be used to manage all your passwords entails.
But what we're interested in is managing our g new P G keys now clicking on this as you can see we have
a number of entries by default.
Do not delete these entries.
These are actually keys used to verify the integrity of updates that tells downloads and the integrity
of packages that you can download through tables and install on your system.
So if you delete them you won't be able to verify the integrity of these packages.
So we're keeping everything here the same.
And what we want to do like I said is create our own keeper so we can share our public key with others
so we can receive encrypted data that can only be decrypted by us.
To do that to create a keeper you can click on the plus sign in here or you can go on file new.
Like I said This application allows you to manage all sorts of keys.
What we're interested in is creating a PDP key.
So I'm going to click on the second entry here and I'm going to click on continue.
Now it's going to ask you for your name.
So in my case I'm using John Wick next it's going to ask you for your email address.
Now it is very important to understand that the people that you'll share the public key with will be
able to see your name and your email address.
Therefore if you want to stay anonymous and protect your privacy make sure you use the fake name that
you created when you created your fake identity and make sure you use your private or anonymous e-mail
in here.
In my case S.J. and S.K. seven at a new dot in we're also going to click on the advanced options to
select the encryption type.
I'm going to keep this at RSA because this is a very strong encryption.
We're going to set the key strength to the highest possible which is four thousand ninety six and you
can also set an expiry date so that your key expires at the date that you specify in here.
Now this would be good if you want to take your security to the next level.
But for this course it's fine.
I'm going to set it to never expire.
I'll keep this ticked and I'm going to click on create to create my keeper.
Now it's going to ask me to set a passphrase for the key.
Make sure you set a strong and long one click.
Okay.
And this program is going to generate your key pair.
And as you can see right here we have a new entry with my keeper.
Now notice the icon here for this keeper contains two keys a silver and gold one.
This means that this is a keeper.
It contains a private key and a public key.
Notice all of the other entries in here contain only one gold key which means that these entries only
contain a public key so these can be used to encrypt data for someone else or verify the integrity of
data.
But there is no private key stored in here.
Now to get more information about any of these entries you can right click and click on properties and
in here you can see information about the owner for example the name John wake like we said it.
The email again.
The same email that we sent it to.
You can see the key idea which can be used to verify the key.
And we'll talk about that later.
And if we go on the details you'll also see the fingerprint which can also be used to verify the key
we actually use this when we downloaded the Tor browser.
If you remember and as we go through this section actually you'll see how the verification steps we
followed to verify the third browser makes sense and all of this will click with that.
Now from here you can also export your secret key which is something that you should never do because
like I said we should never share the secret key the secret key should always be kept privately.
The only time that you might want to do this is if you're gonna completely wipe the system and still
want to use the same key.
You might want to export this.
Store it in an encrypted USP device and then put it on your next installation.
Other than that there is no need to export your key from here.
From here you can also set the expiry so as as shown before we set the expiry to never.
But if you change your mind you can click on this icon and set the key to expire at any date.
You want and going back to the names and signatures you can see again your name and the email associated
with this key and you can click on Add name to add more contacts to be associated with this key.
But like I said be very careful when you're doing this because these contacts will be visible to anybody
that can see your public key.
And like I said in general we will be sharing our public key with a lot of people because this is the
way this works so that they can encrypt data and send it to us.
So now that we have the key power created in the next lecture we're going to talk about how to share
our public key with our contacts and then we'll see how that can be used to encrypt data and verify
integrity.