One of the benefits of using cryptography
is that we can keep our data private,
whether it's data sitting on a disk or sitting in the cloud,
or whether it's data that's being sent over a network.
And we're going to that with encryption.
And the basics for encryption involve locking and unlocking
data.
And think of it like this.
Let's imagine that, I had a chest over here,
and had a whole bunch of really cool stuff inside.
And I could get a padlock, and I could
lock that chest with that padlock,
and then have it shipped over to you. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and then have it shipped over to you.
Now if you want to open that padlock,
I guess you could brute force it open, but more likely,
you're going to use a key.
And if it's just like a simple padlock, it's the same key.
So we might have a couple of copies of that same key.
I have a key to lock it, and use the same key to unlock it.
That's referred to as symmetrical encryption.
Where we use the same exact key to lock and unlock the data.
And protocols that would use symmetrical encryption,
would include a AES, and we use AES with several key links
like 128, 192, 256. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
like 128, 192, 256.
And some of the older protocols that we used to use,
but they're not a security more, including Triple DES,
are also algorithms, encryption algorithms,
that employ symmetrical encryption and decryption.
Basically, meaning using the same key on both sides.
And another option that we have for encryption methods,
is to use, what's referred to as, asymmetrical.
And with asymmetrical encryption, we have a key pair.
So I'm going to say we have, key one, and then
in a different color, will have key two. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
in a different color, will have key two.
Now, mathematically, these keys work together.
And with asymmetrical keys, whatever
we encrypt with one key, whether it's key one or two,
the data can be unlocked with the other key.
So it's a asymmetrical, they're not the same keys,
but they're mathematically paired together
to work together.
And with key pairs, we're going to have private keys, which
implies that if this is R1's key pair, the private key,
he never shares with anybody, and the public key,
he can go ahead and share with the world.
He can share it with R2, he share with R3,
he can share it with anybody, and normally we're WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
he can share it with anybody, and normally we're
going to share our public key via digital certificate.
So if R1 wanted to encrypt data, it
could use its private key, which only it knows,
shipped the data.
And then R2, could use R1's public key,
I'll label that, to go ahead and decrypt that data.
Also public and private key pairs
are used as part of digital certificates
and authentication.
And the big negative about asymmetrical encryption,
is that it does use a lot more CPU,
so generally, we're going to use asymmetrical encryption WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
so generally, we're going to use asymmetrical encryption
algorithms, like RSA for the authentication of a peer,
and verification of who that peer is.
But for the bulk data, we're going
to use symmetrical encryption algorithms, like AES,
to encrypt the bulk of the traffic that's
going to be sent back and forth, between those two peers.
And one other question before I leave this,
is that if we're using asymmetrical encryption,
we've done some work beforehand, To generate the key pairs,
and to get digital service, so we can advertise
our public key, and so forth.
But if we're using just symmetrical encryption,
and we're not using asymmetrical at all, how in the world WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and we're not using asymmetrical at all, how in the world
does R1 and R2, if they're going to be VPN peers,
how in the world do they get the same key to lock
and unlock the data?
And one of the most popular methods for them
to establish a shared key for the encryption and decryption
of data, is use a technique called Diffie-Hellman,
which are the last names of the two gentlemen who created it.
So R1 and R2 could negotiate and run
Diffie-Hellman between them.
Anybody could eavesdrop on that entire conversation,
but at the end of the Diffie-Hellman exchange, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
but at the end of the Diffie-Hellman exchange,
R1 would have keys that match what R2 has.
And anybody who's eavesdropping in the middle,
wouldn't be able to figure out the final result in keys.
So just be aware that we have two peers with cryptography
that are using shared secret keys
that they establish together, is primarily
Diffie-Hellman that's used, to dynamically generate those keys
that both those peers can use.
So in this video, we've taken a look
at the concept of encryption to protect the data, to give us
privacy regarding our data.
So that only the individuals, the parties that WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So that only the individuals, the parties that
have the right keys involved, can
correctly unlock, and actually make sense of the data.
So thanks for joining me in this video.
I'll see you in the next one.
Meanwhile, I hope this has been informative for you,
and I'd like to thank you for viewing.