So let's talk about the basics.
So what exactly is cryptography, cryptography, sort of converting the brain text into unintelligible
format called ciphertext?
And why do we need this conversion means if you want to send a message to a friend by writing an e-mail
on, write a letter and you put it into the envelope and send it to real post-box.
And if other than your receiver, your friend, if anyone sees that it may lack a pregnancy rate and
if the information content more true, then only the receiver should know that information for such
a thing.
We use the cryptography.
So even though anyone sees this, it will be the unintelligible format.
This is the ciphertext so normal other persons cannot read this until they have to convert.
Again, the entries unintelligible format to the plaintext.
So we are sending the unintelligible format and our friend also knows that I'm using some particular
operation and I will tell that operator.
So he'll do the reverse of that operation and he will get the plain text from this unintelligible format
in that way, even though if anyone sees you are in an interview format, the thing that it's like gibberish
or garbage on the receiver, that ciphertext is converted into production using the operation that I
have written now cannot in this production, the unintelligible format.
And this cryptographically policy and integrity president since no one should.
Get that information other than senator and see what an integrity means, the message should be exactly
what it should be.
And in cryptography, we also make it so like it's like a hash of the file of the message.
And that hash is chocolate.
And if it matches, the nonlegal message is confirm that it was not damaged.
If it is correct, it is damage done under the or somebody has modified this message.
So cryptography maintains a privacy and integrity and cryptography is not registered.
Yes.
You do not register.
You do not come from 10 years or 20 years ago.
It from thousands of years ago.
But they do something to the plain text message.
So these ancient Greeks are Egyptians using some symbols which they have in their language, and they
use these symbols instead of plain text and they use these words to convey the message to the receivers.
And as you can see, the almost Daily Mirror images and they will decode the images and they use this
cryptographic techniques.
But today in hundreds, everyone is going to use these mathematical models, our mathematical operations,
to convert this prediction to ciphertext.
OK, now The Imitation Game, this is not any presentation, so this is the name of the movie and I
highly recommend you to watch this because this is an education movie.
And this film was portrayed by a lead actor, by Benedict Cumberbatch.
And Dr. Phil, in this movie, we will see the biography of a great mathematician and also computer
graphics card, Alan Turing.
We are not Alan Turing like Turing machines, and he sided with the Germans Enigma machine in World
War Two and so a lot of lives for England.
And he Benedict Cumberbatch, portrayed the role fantastic there, and you will never get bored watching
this movie.
So once watch this, you will come to know that how Alan Turing deciphered the Enigma cipher.
So in one not by the movie, but that guess you need to learn from others some skills.
You need to learn from others, or even though sometimes others ideas may be useful for you.
So you need to take every advantage for you to be or to solve a problem.
So the talk in this movie, Alan Turing does, he gets a crew and with the crew, he just disappears
within hours.
So if you want to watch the movie, OK, stop the video right now and the next video.
So I'm going to tell you how he found no.
So actually, his girlfriend's friend arrives at the at some restaurant and then they discuss that she
was inside.
So they are excavations.
And then she told that my boyfriend has cheated on me.
So this Alan Turing asked, how did you know that he cheated on you?
So she said that I destroyed him from the doubt.
And then she followed her.
She followed him.
I don't know.
So she said she said that I did.
So Alan Turing came in.
Alan Turing.
Understood that what is the enigma so far, the message just contains a text that is already, I guess
it.
So what is Hitler and all those members does is they send the message like Morning Fighter to morning,
good morning and early warning.
So in that message, there will be some exact non vote like morning, evening, night.
Right.
So Alan Turing, the suit is what?
And he put the this enigma decipher machine already some predicted values like morning and good morning,
evening and night.
He then he ran the Enigma decipher machine.
So within hours, he got the plain text.
So that's how he took that one to go.
So some guessing values and he also saved some lives for the better.
He's a great mathematician.
And also, I highly recommend you to watch this movie.