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We are making a great progress towards asymmetric encryption and photography, we have already discussed



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about what is cryptography and what is symmetric encryption.



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Now, let us move on to the next part of cryptography, which is asymmetric encryption, as the name



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suggests.



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It's not symmetric, which means there are two keys which are used to encrypt and decrypt the message.



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So one key is used to lock your house and different key is used to unlock your house.



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So these two keys in asymmetric encryption, Adonis, public and private key, which means that you



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can unlock the door, you can lock with public key and you can unlock with private key.



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So they are, you know, apair or you can unlock with private key.



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Unlock with public key.



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So the first option here is you have to encrypt with the public key.



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So if that is in a document you want to send over, you have to encrypt it publicly and then you can



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decrypt it private key or you can encrypt with the private key and then decrypt with the public to know



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which one is more secure over here.



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And it's like if Alice wants to send something, both the keys should be of Alice.



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You can't encrypted publicly of Bob and then decrypt with private key of Alice.



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That doesn't work.



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The algorithm is not designed in that way.



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Or you cannot encrypt with Bob's private key and then decrypt with Alice's public key.



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So what you can do here is you can if you want to send me data, if you want to send me a document,



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you can either encrypt with my public key here and then I will decrypt it with my private key.



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Or you can encrypt with my private key and then I will decrypt my public key.



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So which one is more secure now before that?



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Public key is of public knowledge, which means that is a repository and public key is available to



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everyone and anyone can access your public key.



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For example, if you're using WhatsApp, when you are trying to converse, you can see in your settings



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that there's an option, which is this jacket is end to end encrypted, which means that the public



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key of you and your friend is stored in the WhatsApp database and the internal application can access



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any public but private key is stored to you.



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So in a couple of times, I will give you time to think which one is more secure over here.



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So these are the examples of asymmetric encryption, the reversed Shamy Adilman.



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These three people were outstanding minds.



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They developed this algorithm, which is used as asymmetric encryption.



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Then as I explained in the last lecture that Diffie Helmund Exchange uses these terms for elliptic curve



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cryptography.



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It's a very modern cryptography.



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It's hugely vague and advanced.



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And then we have El-Gamal cryptography along that.



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We have the digital signature algorithm nowadays.



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You must have heard about this word very often.



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This word right here, digital signature.



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Every one of us is using digital signature.



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So this algorithm is also very common.



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Yes.



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We are going to talk about this in the coming lecture's.



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And as we know, symmetric encryption was known as private encryption or security encryption, but asymmetric



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encryption is known as public encryption.



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Why it is called public encryption.



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Well, this is a hint for you for this problem here.



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Why this is called as a public encryption.



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We will see in some couple of lectures.



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The drawback is that since there is involvement of two different keys and different prime numbers and



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generators, asymmetric encryption takes more time than symmetric encryption.



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Obviously, you if you have two different keys to unlock and lock the same thing, it will take time.



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Right.



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But if you have one key, you can do it very quickly.



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So asymmetric encryption takes a lot of time as compared to symmetric encryption.



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So these are the examples of asymmetric encryption RSA.



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It has a key generation that go to them and it has a signature generation and then verification algorithm



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in the same way.



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Defilement is this formula.



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So this formula is very important and is equal to Jedi's to key maad be what are the elements, what



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is and what is what is key.



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What is B we will be exploring when we have a different lecture on the defilement key exchange algorithm



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for time being.



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What you need to remember is there are two different keys, just like me.



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It is just make some important points.



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All right.



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So what do you have to remember is you have to take that.



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There are two different keys, public and private key decide which one is more beneficial.



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You have to remember Oddisee, Diffie, Heldman, BSE.



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And the drawback, it is very important.



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So these five to six points are very important.



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If you want to correct any question when it comes to asymmetric encryption, in the next lecture, we



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will be talking about working of asymmetric encryption.



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All right.



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I will see you in the next lecture.