Before, we understand Encryption vs. Decryption let's first understand-
What is Cryptography?
Cryptography is used to secure and protect data during communication. It is helpful to prevent unauthorized person or group of users from accessing any confidential data. Encryption and decryption are the two essential functionalities of cryptography.
A message sent over the network is transformed into an unrecognizable encrypted message known as data encryption. At the receiving end, the received message is converted to its original form known as decryption.
In this tutorial, you will learn
- What is Cryptography?
- What is meant By Encryption?
- What is meant by Decryption?
- Why use Encryption and Decryption?
- Types of Keys
- Difference between Encryption and Decryption
What is meant By Encryption?
Encryption is a process which transforms the original information into an unrecognizable form. This new form of the message is entirely different from the original message. That's why a hacker is not able to read the data as senders use an encryption algorithm. Encryption is usually done using key algorithms.
Data is encrypted to make it safe from stealing. However, many known companies also encrypt data to keep their trade secret from their competitors. 
What is meant by Decryption?
Decryption is a process of converting encoded/encrypted data in a form that is readable and understood by a human or a computer. This method is performed by un-encrypting the text manually or by using keys used to encrypt the original data. 
Why use Encryption and Decryption?
Here, are important reasons for using encryption:
- Helps you to protect your confidential data such as passwords and login id
- Provides confidentiality of private information
- Helps you to ensure that that the document or file has not been altered
- Encryption process also prevents plagiarism and protects IP
- Helpful for network communication (like the internet) and where a hacker can easily access unencrypted data.
- It is an essential method as it helps you to securely protect data that you don't want anyone else to have access.
Types of Keys
Symmetric Key:
Symmetric-key encryption are algorithms which use the same cryptographic keys for both encryption of plaintext and decryption of ciphertext.
Asymmetric Key:
Asymmetric encryption uses 2 pairs of key for encryption. Public key is available to anyone while the secret key is only made available to the receiver of the message. This boots security.
Public Key:
Public key cryptography is an encryption system which is based on two pairs of keys. Public keys are used to encrypt messages for a receiver.
Private Key:
Private key may be part of a public/ private asymmetric key pair. It can be used in asymmetric encryption as you can use the same key to encrypt and decrypt data.
Pre-Shared Key:
In cryptography, a pre-shared key (PSK) is a shared secret which was earlier shared between the two parties using a secure channel before it is used.
Difference between Encryption and Decryption
| Parameter | Encryption | Decryption |
|---|---|---|
| What is | It is a process of converting normal data into an unreadable form. It helps you to avoid any unauthorized access to data | It is a method of converting the unreadable/coded data into its original form. |
| Process | Whenever the data is sent between two separate machines, it is encrypted automatically using a secret key. | The receiver of the data automatically allows you to convert the data from the codes into its original form. |
| Location of Conversion | The person who is sending the data to the destination. | The receiver receives the data and converts it. |
| Example | An employee is sending essential documents to his/her manager. | The manager is receiving the essential documents from his/her employee. |
| Use of Algorithm | The same algorithm with the same key is used for the encryption-decryption process. | The only single algorithm is used for encryption and decryption with a pair of keys where each use for encryption and decryption. |
| Major function | Transforming humanly understandable messages into an incomprehensible and obscure form that can not be interpreted. | It is a conversion of an obscure message into an understandable form which is easy to understand by a human. |
Summary
- Cryptography is used to secure and protect data during communication.
- Encryption is a process which transforms the original information into an unrecognizable form.
- Decryption is a process of converting encoded/encrypted data in a form that is readable and understood by a human or a computer.
- Encryption method helps you to protect your confidential data such as passwords and login id.
- Public, Private, Pre-Shared and Symmetric are important keys used in cryptography.
- An employee is sending essential documents to his/her manager is an example of an encryption method.
- The manager is receiving the essential encrypted documents from his/her employee and decrypting it is an example of a decryption method.
