Encryption or transforming the original data to a cryptic or

uninterpretable format.

Decryption or converting the encrypted data back to its original

form.

In each cryptographic algorithm, we use two different types of

cryptographic keys for the encryption and decryption of the data,

which are as follows:

Symmetric cryptography

Asymmetric cryptography

1.5.1.1 Symmetric Cryptography

In symmetric cryptography, there is only one cryptographic key that

is used for both encrypting as well as decrypting the data. This

approach is easier and yet has limited functionalities and use cases.

1.5.1.2 Asymmetric Cryptography

Public-key cryptography, also known as asymmetric cryptography,

uses a pair of keys, which are as follows:

Public key, that can be visible to others

Private key, that stays only with the owner

While one key can be used to lock the message, the other can

unlock it. These two keys can be used in a variety of different ways;

look at the following example:

Alice wishes to send a secret message to Bob. Alice would

encrypt the transaction with Bob’s public key and only Bob can

decrypt it using his own private key.

Alice signs a document using her private key, also known as

“Digital Signature”. The others who know Alice’s public key

can validate that the document is actually signed by Alice.

The following are the different types of asymmetric cryptography:

1.5.1.2.1 RSA