Cryptography is classified into two categories based on the types of keys and encryption algorithms :
* Symmetric Key Cryptography (Secret key)
* Asymmetric Key Cryptography (Public key)
Let’s take a closer look at each type.
Symmetric Key Cryptography : Also known as Secret Key Cryptography, private key encryption encrypts data using a single key that only the sender and receiver know. The secret key must be known by both the sender and the receiver, but should not be sent across the channel; however, if the hacker obtains the key, deciphering the message will be easier. When the sender and the receiver meet on the handset, the key should be addressed. Although this is not an ideal method. Because the key remains the same, it is simpler to deliver a message to a certain receiver. The data encryption framework (DES Algorithm) is the most widely used symmetric key system.
Asymmetric key cryptography : Asymmetric key cryptography, also known as public-key cryptography, consists of two keys, a private key, which is used by the receiver, and a public key, which is announced to the public. Two different keys are used in this method to encrypt and decrypt the data. These two distinct keys are mathematically linked. They are sold in pairs. The public key is accessible to anyone, whereas the private key is only accessible to the person who generates these two keys.
For example, Bob wants to send an encrypted message to Alice, and they agree to encrypt his message using public-key encryption. The receiver initiates public key encryption to encrypt the sender’s message. The receiver, not the sender, initiates the public key method to encrypt the sender’s message. Everyone has access to the public key. The receiver, Alice, is the only one who has access to the private key. The following is how it works :
Step 1 : Alice generates two keys: one public and one private. Alice stores the public key on a public key server that anyone can access.
Step 2 : Alice informs Bob of the location of her public key.
Step 3 : Bob obtains Alice’s public key by following Alice’s instructions.
Step 4 : Bob composes a message and encrypts it with Alice’s public key. Bob sends Alice the encrypted message via the network.
Step 5 : Alice decrypts Bob’s message using her private key.
