What is Encryption & How Does it Work?

There is nothing new about encryption. It has a prolonged history. Ancient Roman and Greeks sent messages in secret language, only interpretable with a secret key.

In today’s modern world, the importance of encryption is more than ever and you will see its application across vast number of fields.

Various applications, such as WhatsApp and Gmail, use encryption process. Since it is very easy for hackers to steal your data and information, the process of encryption is the best way to protect anything communicated or store online.

In order to understand what is encryption and how does it work, this article provides all the information in a simple language. So if you have little to zero knowledge related to encryption, then this guide is for you.


What is Encryption?

If you haven’t seen the movie “Imitation Game” yet, then you should watch it ASAP! It’s all about how British M16 agency breaks the Nazi encrypted codes with the help of mathematicians in 1939.

The mathematics professor builds a team, which analyzed the encrypted messages of Nazis and then made a machine to decrypt those messages. This movie is the best way to develop an understanding about encryption process without getting bored.

But if you are looking for a quick simple answer, encryption is a process which converts the simple text into ciphertext (encrypted text) using algorithm codes and keys. Now the ciphertext is only interpretable if the receiver has the right code and key.

In this way, you are safe from hackers, as they are unable to steal your valuable data. To make it simpler, let see the pictorial example of the encryption process.

What is Encryption Process


Why is Encryption Important in the Modern World?

When you use an online messaging application to communicate with your friends and family, it is important to keep your conversations private.

Without any security, when John and Mark message each other, there might be a chance that hackers and others alike could eavesdrop on what they converse.

These attackers can also customize the text you send and reroute them. In technical terms, this is known as Man in the Middle Attack. These attacks happen when the application channel passes the messages in simple text.

Because of these risk, most of communication applications and other programs use encryption to make your messages and data safe from hackers.

But in today’s high tech world, in order to make your data safe from hackers is not that easy even when you are using encryption process. For this, it is important to understand how encryption works.


How does it Encryption Work?

Until now, we think you get the general idea of what is encryption and why it’s a necessity. Now, it is time to explain how does it works in the modern world. For this, it is necessary to know how many types of encryption are available.

Symmetric Encryption

This type of encryption uses the same basic approach, it converts simple text into encrypted ciphertext by using a key. The receiver interprets the ciphertext message into simple text using the same encryption key. To make it simpler, apply this to our scenario.

When John sends the message to Mark, he coverts plain text into ciphertext with a symmetric encryption key. Now Mark gets the message, he converts the cipher text into plain text with a similar key. This way hackers cannot access the actual contents of the messages due to encryption.

The symmetric key is created per session and the same key is disabled for subsequent messages.

Symmetric Encryption


  • Expansibility: The major issue with asymmetric encryption is expansibility. If 100 individuals were using an application to communicate with one another, all the participants would require different encryption keys to manage a safe channel.
  • Key Allocation: If we suppose that both John and Mark would have symmetric key, so how do they obtain the encryption key in the first place? If John creates a key and forwards it to Mark, the hacker could attack the data if any further messaging occurs.

So, what is the solution to these issues?


Asymmetric Encryption

Although, asymmetric encryption uses the same basic encryption process similar to symmetric encryption, it uses two keys – a public key and a private key.

So, at first, the simple text is encrypted with a public key. Now the encrypted text is only interpretable (decrypted) with the related private key and the other way as well.

By using two encryption keys (public & private), users get over the issue of two symmetric keys (expansibility). But, the process of asymmetric encryption is slower than symmetric. So the developers use both together.

Asymmetric Encryption


So how does the encryption process work? The public encryption key is available to every individual but the private encryption key belongs to the corresponding person only.

When John is going to text Mark, initially he produces a symmetric session key. In the next step, he encrypts it with Mark’s public encryption key. Mark obtains his own private encryption key. Now he is the only individual who can interpret (decrypt) the text.

Using this encryption process, the session key will be used to encrypt and decrypt text. The issue of key allocation is resolved without slowing the speed. This is because the asymmetric encryption process is used in beginning.

Even though this process resolves previous issues, they are not finished. It means your security and privacy might be comprised.


  • Verification & Authentication: what is the surety if we are using public encryption key in the beginning? It is possible that the public key obtained can be from any hacker.
  • Data Integrity: there is no way to find out that the text has customized at the time of sending process.

So what now?  

What is Encryption


How to Solve Encryption Issues?

Digital Signature and Certificates

The verification needs a reliable procedure. With the assistance of verified and reliable authority such as Certificate Authority (CA), it confirms that these public encryption key belongs to the specific individual. So, each application user verifies themselves (provides individual personal information) with CA.

Now, if John wants to text Mark, he can verify, with the assistance of CA that the public encryption key belongs to Mark. The same process is used by HTTPS on the internet. So, the issue of verification and authentication is resolved by using digital certificates.

What is Encryption-How it Works

The next issue is data integrity. Digital signature resolves this problem. The procedure for solving this issue is a bit complex but we divide it into steps:

  1. When John wants to text Mark, he initially develops a session key and encrypts the Mark public encryption key with it. Now let’s name this Z1.
  2. Now he produces a hash text from available hashing algorithms. A hash text is used for one-sided communication from multiple large bytes to limited one It is impossible to get an actual text from the hash algorithm and it can never be the case that two texts have the same hash algorithm.
  3. Once the hash is developed, John encrypts it with his private encryption key. This process is known as a digital signature, as it provides the feature to verify the text sent by John without any customization.
  4. Now the actual text and digital signature is encrypted with symmetric key (session key), let’s name this Z2.
  • Z1: John-Key (Public) > (Symmetric Key)
  • Z2: Symmetric Key > (Text + Digital Signature)
  1. John sends both Z1 and Z2 to Mark. Mark is the only person who obtains the corresponding private encryption key. Therefore, only Mark can interpret (decrypt) Z1 and get the symmetric key to access Z2 (redeem the text and digital signature).
  2. Then Mark gets John’s key (public) to interpret the digital signature and recover the hash text. He measures hash text length and if it is same as in the initial step, it means there is no data integrity threat and the communication is secure.


Wrapping Up

We hope you get the deep understanding of what is encryption and how does it work. The same process of encryption is used by VPN services. Top VPN services use AES 256 military-grade encryption, so in order to secure your data and information online, you can avail this kind of services.

If you have any query regarding encryption, just drop us a comment below.


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Senior Editor

Aazii's Biography :

A privacy advocate by day and a binge-watcher by night, Aazii loves to write about online security, internet freedom, and all the latest technological trends. Finding ways to secure any sensitive data and protect against existing and emerging cyber threats is his passion. Follow him on Twitter to stay in touch with his work!

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