All right, in the last lecture, we did talk about the working of asymmetric encryption.
Now we will talk about the walking.
I'm sorry, in the last lecture, we talked about the asymmetric encryption in this lecture.
We will talk about working of asymmetric encryption.
So right here we have our phone, Bob, and we have Alice.
Now, Bob wants to send some important documents to Alice over the Internet.
So let us see, using asymmetric encryption how he can securely send those important documents.
Well, let us consider this is the original document that Bob has and he cannot send the document as
it is.
Right.
He has to encrypt it because he wants to send it securely.
So this is Alice's public, right.
So if any one of you or has confirmed that you have to encrypt with public key and then decrypt with
private key of the same person, then you are right now, if if I wanted to encrypted private key,
it's not possible because I don't have the other person's private key.
It has to be it.
The private key is supposed to be with the person himself.
You're not allowed to share your private key or the app doesn't allow them to share the private keys.
So what you can do is you can take the public key, which is publicly available, so you can take the
public key, you can use encryption algorithm and then you can get the encrypted document.
Finally, what you can do now, once you have this encrypted document, it's encrypted with the public
right of public.
You will send this document now.
Alice will receive this encrypted document.
What she will do is she will use her private key, because if you have encrypted with a public key,
you can only decrypt with private key.
And since Bob has encrypted with Alice's public key, she can only decrypt with her private key.
And Alice's private key is with her.
So Alice can then run the decryption algorithm and then she will get the original document.
So what you can understand here is this is the encryption process and this is the decryption process.
So in this way, these two different keys are used for asymmetric encryption.
So the bottom line here is you have to encrypt with the receiver's public key and then you have to decrypt
with receiver's private key.
This is the base working of asymmetric encryption.
Make sure that you understand understood this working because this is the exact same working we are
going to use in case of digital signature algorithm.
Now, since here there are two different keys used, the protection is more, but again, it takes more
time.
So right now you're only seeing only one document.
But in the Internet, thousands of millions of documents and e-mails get exchanged in one second.
So, you know, you have to have some method in order to make symmetric encryption work.
So what is that method we will see in the next lecture where we'll have a look at the Diffie Hellman
key exchange algorithm.
So if you have any doubts regarding asymmetric encryption or symmetric encryption, you may ask us through
the question and answer portal.
We are always welcome to solve your doubts.
All right.
Let us get started now with Diffie Helmond Exchange algorithm.