What is Cryptography: A Complete Guide

Cryptography is something you encounter more times than you realize. Even if you weren’t aware, you might have used cryptography to send notes in secret to your friends. To define it in more technical terms, cryptography is the science or art of encrypting any kind of sensitive information which once used to be under the governance of the military, academia, and government. The recent technological progression demands cryptography to permeate all different facets of our everyday life. Let’s read about What is Cryptography.

From your smartphone to online banking, every operation you see relies on cryptography to keep your data safe and secured from any vulnerabilities. 

While cryptography comes with its inherent share of complexities, many people have often left the discussions associated in the hands of black hat hackers, conglomerates, and MNCs. But with the vast amounts of data that is being circulated on the internet, it can be weaponized or used for organized disruption. Presently, given the circumstances, it is more important than ever to know how you can successfully protect yourself from all kinds of ill intentions and fraudsters. 

This piece will delve into the fundamentals of cryptography. You will be able to comprehend what cryptography is and how you benefit from this. The piece will further talk about ways cryptography is used or has been used throughout the years. It will also explain the importance cryptography holds in the world, be it online or otherwise. It will also talk about the vulnerabilities associated with cryptography and how it is not the ultimate solution when it comes to data protection. 

Historical Overview of Cryptography 

Information has been one of the most valuable assets for human civilization. Naturally, the history of cryptography goes way back even before computers came into being. And our abilities to hide or keep information away have often shifted war, toppled the government, and brought power to political parties. Clay Tablets from 1500 BC has shown signs of encryption which was used to protect information. Hebrew scholars have also made use of alphabetical ciphers around 500 to 600 BC. 

Cryptography also came in handy during wars. Especially during the American Revolution, British forces employed various kinds of cryptography to talk between generals. Using ciphers, they could encode important messages which were delivered to the generals. Even during the Second World War, there came electro-mechanical and mechanical machines for encryption that were used by almost all the participants of war. The best-known machine that was used in WW II was the one used by Germans. It was an electro-mechanical rotor cipher called the Enigma Machine. The country used this device to encode all their battle plans along with other sensitive data for communication during the war. 

Alan Turing who was an English cryptanalyst could employ various techniques to break several of these ciphers. Turing played a pivotal role in deciphering these coded messages which helped allies defeat the Nazis in critical battles. Many still believe that his work shortened the war, at least by two years, saving millions of lives. 

As of modern implementation, you can look at banking. Every bit of records and information transmitted between payment processors and vendors is encrypted. And, since most of this information is kept in a large database, cryptography becomes a requirement. In case they were being transmitted without encryption, it would be an open invitation for hackers and they will deplete every bit of money banks or institutions have. Banks these days have advanced cryptographic methods implemented for advanced encryption which keeps your valuable assets out of the hands of hackers. 

How does Cryptography work? 

This section will cover the ways cryptography works. At its fundamental level, cryptography requires two steps i.e. encryption & decryption. The encryption involves a cipher that encrypts plaintexts and converts them into ciphertext. Decryption, however, uses the cipher to convert the ciphertexts back to plaintexts. A cipher can be described as an algorithm that encrypts and decrypts messages. Here’s an instance of how it works 

So, if you want to encrypt the word “Hello”, the plaintext here will be “Hello”. Now if you apply Ceaser’s Cipher which is one of the simplest encryption forms, you convert your plain text to ciphertext. 

So, with this cipher, you just need to shift each of your letters to a set number of spaces either up or down the order. So, a letter has corresponded to certain letters or alphabets. To keep things simple, here’s an example: 

  • A becomes B 
  • B becomes C 
  • C becomes D 

By applying this, you can convert any plaintext to ciphertexts. This, however, is a simple form of cipher which anyone with basic encryption knowledge can decipher. But this was to demonstrate how encryption worked. 

A brief overview of Polymorphism 

This is a bit advanced as a topic. Polymorphism applies an added layer of encryption to your messages. But the subject is a bit deeper than it seems to be. So, to put it in simpler words, polymorphism can be defined as a cipher that changes every time it’s used. So, what polymorphism does is further shift the letter. The shift happens every time it is encoded. It can only be deciphered by someone who professes in decrypting polymorphic ciphers. Polymorphism is seen in algorithms that encrypt software, cloud-based information, and computers. 

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Why should you care about Cryptography? Why is it so important?

Cryptography is one of the best methods that are available today which protects your data and sensitive information. The unique calculation/code/key combinations that encrypt or decrypt data make it an efficient way of keeping your information safe and secured. 

If you are using the internet for capital transfer and asset protection, then cryptography is critically important for you. 

Without the presence of cryptography, your messages sent or received can be intercepted or read by anyone potentially. Every bit of your information is subject to leak without cryptography. 

Types of Cryptography 

There are around four kinds of cryptography that are in use today, protecting our data from online hacks. 

  • Hashing 

Hashing is designed to take message strings of any given length to produce a specific length base hash value. 

  • Symmetric Cryptography 

This is one of the simplest forms of encryption which involves the use of one secret key to encrypt and decrypt data or information. This is one of the best-known methods available as of yet. 

  • Asymmetric Cryptography 

Asymmetric cryptography uses public and private keys. The public key encrypts data or other messages while private keys decrypt the information. So, a message that has been encrypted with a public key can be decrypted with a private key. 

  • Key Exchange Algorithms 

This kind of algorithm allows a safe exchange of keys with any unknown parties. Users don’t have to share any information during an encryption key exchange. The end goal is to make a custom encryption key that can be used by both parties. 

Cryptography and its functions 

Cryptography has a lot of modern implementations in the present world. Its 4 main functions can be categorized as follows: 

  • Authentication

It is a process that ensures that both the parties are who they are on either end of the connection. If you have noticed, there is a usual authentication type that you encounter while browsing or visiting a secure website. These secure websites use SSL certification which is proof that the owner owning the website has a public cryptographic key and that you are connected to the correct server. You will usually see a green URL or a closed padlock which indicates that the website you are connected to is secure. This can be handy when you are shopping online or paying bills via online payment methods. 

  • Non-repudiation 

In the former days of e-commerce dealings and online banking, some users would approve a transaction and later claim to have no recollection of such approval. Thus, cryptographic non-repudiation tools were made to make sure that the user is approving of the transaction in real-time. So, that they can’t claim a refund on the grounds of not approving such a transaction. This has largely prevented fraudulent activities from happening. A bank can now take measures against such events from ever happening by implementing non-repudiation methods, consisting of digital certificates, hashed data et al. 

  • Confidentiality 

This essentially keeps your data secure and privatized which is probably the most important security application of cryptography. The current scenario is that people are prone to data breaches due to a lack of cryptography protocols. To ensure confidentiality, make use of the methods that are already in use. 

  • Integrity 

Cryptography can prevent people from ever viewing or changing your data in transit. It also prevents incidents involving data tampering or leaking sensitive information to denigrate reputation. 

Is Cryptography foolproof?

Cryptography dramatically increases the level of securities but it is not absolute. There have been instances of hacking and attacks happening every now and then. Even though these hacks happened out of vulnerabilities visible, cryptography is not always a foolproof method. But that doesn’t mean that you should give up, use the methods that are available for you. Ensure encryption to protect your valuable assets.


This article aims to give an overview of the history associated with cryptography, its modern implementation, and its functions. While there can be a number of ways to enable cryptography, the best way to keep your devices safe is to employ modern encryption methods, like for instance use a VPN for your online activities. 

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