Let us get started with the fundamentals of cryptography.
Now, why do we use cryptography before we answer that question?
Cryptography goes way back into the history.
Basically, cryptography was used to deliver messages during wartime and battles.
So when cryptography was basically used to deliver the message from a king to the army so that the enemy
wouldn't understand what exactly they're trying to tell.
And it goes way back to German.
I'm sorry, it could be back to Greek and Roman period where Caesar cyphers and streamside for substitution
ciphers were basically used.
Apart from that, modern topography got a great boom in the in the 20th century or in the late 19th
century.
So if you've seen a movie, The Imitation Game of, uh, in which depicts the use of cryptography of
Benedict Cumberbatch.
So he has played the role of Alan Turing really well.
And I must say that if you have interest in cryptography, you must go and watch that movie because
it explains everything, how his team was able to break the Enigma machine of Germans and which successfully
led the attack of Normandy and how England won the war.
Apart from that, cryptography is basically nothing but conversion of a regular plain data into a complex
series of random alphabets or whatever you pass into the algorithm.
Output is a gibberish text.
You don't understand what exactly is the output?
And there are many algorithms used to do exactly the output to give the output.
Again, cryptography is used to prevent the confidentiality and integrity of data.
We have already seen the elements of information security in the introduction part of this course.
So what is confidentiality?
Basically, confidentiality is to avoid unauthorized access to the information which is supposed to
be known for only authorised people.
And integrity is maintaining the state of data.
So to have to achieve all these objectives, we need to keep data secure.
And how do we keep data secure by basically using cryptography?
So that is the main reason we use cryptography.
And cryptography has become very common these days.
These transactions, you know, that happen through the Internet are all encrypted or whatever you send
through emails is also encrypted and then decrypted at the receivers end in order to maintain the confidentiality.
So almost everything, everywhere cryptography is used and it is very common.
And hence that is why it is very important to understand cryptography.
Now, as I told you in the last lecture, what most of the people do is to directly dive into the mathematical
formulations of cryptography.
Well, if you are really an expert, you can do that.
But what I suggest to you is you first understand what cryptography is and then you may try to learn
the mathematical point of view.
So cryptography, as I said, is very important for data privacy nowadays, we all know how important
data is to you.
That is why if you want to maintain a data privacy, you have to have cryptography in place.
Now, I'm not saying cryptography is the only solution to prevent data.
It can lead to privacy of data.
And that is why when it comes to ISO twenty seven thousand one, that is information security management
systems, they do have cryptographic controls in place in order to check whether the organization is
following those controls while maintaining the integrity of information systems.
All right.
So let us not let us have a look at the elements that helps us to achieve during cryptography.
So basically, cryptography helps in maintaining the information confidential.
It also helps to avoid any unnecessary edits to the data.
And hence it is in keeping the data integrity using cryptography.
You can also achieve availability of data so that if data is secure, it can be available to you when
and wherever it is needed.
We can also maintain the authenticity of people using cryptography.
We have already discussed about authentication and access control previously in this code.
So if you want to know more about that, I suggest you to go back to that section.
All right.
So, yes, authenticity, validating the user's identity, using cryptography is also very common.
I hope you've understood why we need cryptography.
Basically keep these elements in mind.
So if anyone asks you the main reason behind using cryptography, you just have to answer these three
points.
Cryptography helps in achieving confidentiality, integrity and availability of information security.
And you'll get full marks, OK, in the next lecture.
What we'll do is we'll start with these two types of cryptography, which are of very common.
Again, there are many types.
OK, I'm repeating this word course is not for those people who want to master cryptography.
All right.
Because it would take a lot of time to have a course on cryptography.
We are just going to go through fundamentals so that we will understand cryptography really well, because
it is more important for you to understand cryptography than to have complete knowledge.
So in the next lecture, we will talk about these two types of cryptography.
And I'm pretty sure that my explanation will make it really easy for you to, you know, keep those
concepts in your in your mind.
It will really help you to clear the things.
All right.
Keep this momentum going and doing a great job here.
You have almost completed the course now.
It's just some sort of lectures which are remaining will soon get done with the entire course.
I will see you in the next lecture.