Encryption and Decryption: What’s the Difference?


To understand what is encryption and decryption in communication protocols, it is essential to understand the meaning of cryptography. Cryptography refers to securing information and messages in the communication process with the use of two primary functions, which are encryption and decryption. Therefore, encryption and decryption facilitate the secure relaying of messages from one party to another and prevent unauthorized individuals from accessing confidential data.

  1. What are Encryption and Decryption?
  2. How it Works
  3. Differences Between Encryption and Decryption

1. What are Encryption and Decryption?

In cryptography encryption and decryption, data encryption refers to the process of converting sensitive information into coded text that cannot be understood or recognized by a third-party. 

Once this coded message reaches the desired recipient, decryption is undertaken. Decryption is the process of converting the coded text back into legible and understandable data in its original form, thereby completing the chain of secure communication. This is done with the help of encryption and decryption algorithms to ensure that no hacker who attempts to intercept the communication can gain access to sensitive information that can be misused.

2. How it Works

The encryption and decryption process is undertaken primarily as a data protection technique. In computing terms, unencrypted data, such as emails, text messages, or other sensitive communications, are called plain text. Such plain text, if communicated without encryption protocol, can easily be intercepted, accessed, and misused by hackers, which is why the reliance on encryption and decryption techniques has increased.

The plain text is encrypted by using an encryption algorithm as well as an encryption key that converts this plain text into a coded form, which is referred to as ciphertext. In turn, this ciphertext can only be converted back to its original condition if the appropriate key is applied to it in the process of decryption.

Encryption, therefore, scrambles the content of a message or communication in such a way that it is undecipherable by any unauthorized party who manages to get their hands on it. Therefore, only the sender and receiver hold the keys to affect the communication, which is the easiest way to ensure smooth and secure communication of confidential or sensitive data. Modern encryption algorithms ensure confidentiality and help by offering security tools such as authentication, integrity, and non-repudiation. Authentication helps to verify the origin of the message being sent.

In contrast, integrity allows the recipient to ensure that the message has not been tampered with or changed since it originated at the source. Non-repudiation helps ensure that no individual can deny the sending of a message once communicated via an encrypted channel. The encryption key could be either symmetric or asymmetric. Symmetric keys are used to encrypt and decrypt messages, whereas asymmetric keys are those where only the public encryption keys are shared. Still, the private decryption keys are not divulged to anyone.

To understand what is encryption and decryption with an example, imagine the following situation when a company comes into a contract with another company on certain terms that they desire to keep confidential. However, they fail to use encryption and decryption methods to protect their communications, which are eventually intercepted by a hacker who makes all the contract public’s details. This is why encryption is so important since it would have avoided the situation wherein the information that is supposed to be confidential has fallen into an unauthorized third-party’s hands. 

3. Differences Between Encryption and Decryption

As we already know, encryption is the process of converting sensitive information into secure code or text that cannot be intercepted and further accessed and understood by the intended recipient of the information through decryption. The primary difference between encryption and decryption, but many more such differences exist, and they have been listed below.

  • Objective: The main aim of the process of encryption is to protect confidential or sensitive information from malicious attempts to steal data by converting plain text into ciphertext. On the other hand, decryption’s primary objective is to re-convert the encrypted ciphertext back to readable and understandable plain text that conveys the original message to the recipient. 
  • Origin: The encryption process originates at the sender’s end before the message is transmitted to the desired receiver. The receiver starts the decryption process once he receives the encrypted message, and this completes the chain of communication.
  • Usage: To encrypt data, a public key or a secret key can be used. For decoding of information scrambled with a mystery key, a similar mystery key can be utilized. In the case of asymmetric key protocols, the public key is used for encryption, whereas a private key is always used to decrypt the data.
  • Example: If an employee forwards confidential documents to her boss, a public key or a secret key may be used to encrypt her data for secure communication. On receiving the email, the boss is allowed to view it once the secret key or private key is always used to decrypt the message sent, thereby allowing him access to the documents. 


In today’s world, where each person communicates with many others for a variety of reasons, data encryption is a necessity and an essential practice and not a privilege or choice. Millions of documents, sensitive information, private messages, and media are shared daily over the internet and other networks, which are susceptible to be intercepted and misused by hackers with malicious intent. Such unfortunate circumstances could cause not just loss of data but also significant duress and stress. Many cybersecurity experts believe that the best form of encryption is automatic and not manually initiated.

All information is transferred in and out of any computer system must automatically be encrypted and not just on those occasions where the user believes that the data is sensitive or worth securing. Such practices can ensure safer and more secure exchanges of data in the information age.

So, have you made up your mind to make a career in Cyber Security? Visit our Master Certificate in Cyber Security (Red Team) for further help. It is the first program in offensive technologies in India and allows learners to practice in a real-time simulated ecosystem, that will give you an edge in this competitive world.

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