Cryptography Examples: The 3 Codes You Need to Know (2023)

By Tibor Moes / Updated: June 2023

Cryptography Examples: The 3 Codes You Need to Know (2023)<br />

Cryptography Examples

Imagine you’re sending a secret note to a friend in class, but you don’t want anyone else to read it. So, you develop a secret language, only you two understand. Cryptography is like this secret language, but for digital communication, shielding our most important information from prying eyes!


Cryptography is the digital equivalent of secret codes. It’s a method to hide information by transforming it into unreadable text, which can only be decoded by those who have the right ‘key’. It ensures our digital data—emails, bank details, personal info—remain secure.

Example 1 – Caesar Cipher (circa 58 B.C.): Named after Julius Caesar, this is one of the earliest known cryptography examples. Caesar would shift the letters in his military commands by a fixed number of positions in the alphabet to keep them secret from his enemies. For example, with a shift of 1, ‘A’ would become ‘B’, ‘B’ would become ‘C’, and so on.

Example 2 – Enigma Machine (1920s to 1940s): Used by Germany during World War II, the Enigma Machine was a complex encryption device. It used a series of rotating mechanical rotors to scramble plaintext messages into ciphertext. The machine’s settings were changed daily, making it extremely difficult for Allied forces to decipher intercepted messages until they captured an Enigma machine.

Example 3 – RSA Algorithm (1977): This modern-day cryptography method is widely used in our digital world. RSA (Rivest-Shamir-Adleman) is an algorithm used to encrypt and decrypt messages in systems like email, and is an essential component of secure internet communication. It’s based on the mathematical difficulty of factoring large numbers, a problem which is easy to understand but, as yet, has no efficient solution.

Don’t become a victim of cybercrime. Protect your devices with the best antivirus software and your privacy with the best VPN service.

Cryptography Examples In-Depth

Caesar Cipher (circa 58 B.C.)

Take a moment and think back to when you were a kid, playing around with your friends, and maybe inventing your own secret language. You swapped letters or replaced words with others so that no one else could understand. It was fun, it was exciting, and, unbeknownst to you, it was an early brush with cryptography!

One of the simplest and most historic examples of cryptography comes from a time long, long ago, way before computers, the internet, or even electricity! In the hustle and bustle of ancient Rome, a clever chap named Julius Caesar was making a name for himself. Caesar, a man as strategic in his personal correspondence as he was in his military campaigns, devised a simple yet effective way to send secret messages to his generals.

You’re probably wondering, “But how could Caesar, living in an era far removed from modern technology, come up with such an advanced concept?” And the answer lies in the beauty of simplicity.

Caesar’s method, known today as the ‘Caesar Cipher,’ worked a bit like those secret languages you used to create as a child. Here’s how it went: Take the alphabet, and for each letter in your message, swap it with the letter that’s a few places down the line. For instance, if you’re using a shift of 1, ‘A’ becomes ‘B’, ‘B’ becomes ‘C’, and ‘Z’ goes full circle and becomes ‘A’.

The fun part was, to anyone else looking at this scrambled message, it would appear as nonsensical gibberish. But for those in the know, with the understanding of the shift used, it could be translated back to its original form. Voila! A message hidden in plain sight, but readable only by those Caesar wanted to read it.

Though it may seem overly simple to us now, especially compared to the complex algorithms used in today’s digital world, the Caesar Cipher was indeed revolutionary for its time. It provided a cloak of secrecy around sensitive military information, thereby influencing the course of many battles, and ultimately, the expansion of the mighty Roman Empire.

But as with all technology, the Caesar Cipher eventually met its own ‘Brutus’. As more and more people got wind of this swapping trick, the code could be easily broken. However, its influence lives on as the progenitor of more complex ciphers and codes used throughout history, and its principles form the building blocks of modern cryptography.

So, next time you’re sending a secret note, or typing a password, spare a thought for Julius Caesar, who, in his own simple way, set the groundwork for the cryptography that protects our data today. Caesar Cipher, the original secret code, truly was a giant leap for mankind, even in sandals and a toga!

Enigma Machine (1920s to 1940s)

Imagine you’re trying to solve a Rubik’s Cube, that classic 3D puzzle that’s driven people to the brink of frustration for decades. Each twist and turn you make changes the configuration of the colors. The goal is to figure out the right series of moves to align all colors on each side. Now, imagine you’re doing this but with words instead of colors, and you’re starting to get a feel for the complexity of the Enigma Machine.

Stepping into the darker period of the 1920s to 1940s, in the midst of World War II, Germany was using a highly complex device that looked like a typewriter on steroids. This was the Enigma Machine, a piece of technology so advanced for its time that it could transform an ordinary text into a scrambled message that left the best Allied codebreakers scratching their heads.

Here’s how it worked: Let’s say you want to send the word “ATTACK”. You’d press the ‘A’ key on the Enigma Machine, but instead of ‘A’, another letter would light up on the display. Each keypress resulted in a different letter, thanks to a set of rotating mechanical rotors inside the machine that scrambled the message. What’s more, the configuration of these rotors was changed daily, making it even more challenging for anyone trying to crack the code.

The resulting coded message would be transmitted in Morse code to the German forces. Upon receiving the message, they would input the scrambled text into their own Enigma Machine, which was set to the same daily settings as the sender’s. The machine would then reverse the encoding process, spitting out the original message.

It was a cryptography dance of sorts, where sender and receiver needed to know the exact moves (or in this case, rotor settings) to decode the message successfully. And for a time, it worked brilliantly, providing the Germans with a significant advantage by securing their communications from Allied interception.

However, just like the Caesar Cipher, the Enigma Machine too met its downfall. The tide turned when the Allies captured an intact Enigma Machine and its codebooks. This event, combined with the exceptional work of mathematicians and engineers at Bletchley Park in the UK, allowed the Allies to start deciphering German messages, contributing significantly to the outcome of the war.

The Enigma Machine stands as a testament to human ingenuity and a reminder of the power and importance of secure communication. Despite its fall, its concept lives on, inspiring the development of newer, more robust forms of cryptography. Even today, as we log into our email or make an online purchase, we can thank these cryptographic roots for the privacy and security we enjoy.

RSA Algorithm (1977)

Have you ever tried to solve a puzzle that seems simple at first glance, but as you delve deeper, it becomes incredibly complex? That’s what we’re dealing with when we talk about the RSA Algorithm, a staple of modern cryptography. The RSA Algorithm is like a superhero in the world of cryptography. It’s there in the background, silently protecting us, all while maintaining an unassuming disguise.

Fast forward to 1977, far from the battlefields of ancient Rome or World War II, three mathematicians – Ron Rivest, Adi Shamir, and Leonard Adleman, sat down at MIT and created an encryption algorithm that would become the backbone of secure digital communication. They named it RSA, using the initials of their last names.

The RSA algorithm works a bit like a digital lock and key. It’s a bit tricky, but let’s break it down. Imagine you have a box (this represents your data), and you want to send this box to a friend securely. You have a padlock but no key. However, your friend has the key to your padlock. You lock the box and send it off. Now, only your friend, with the right key, can open it. This is the essence of RSA.

Now, the magic of RSA is rooted in the world of numbers – large prime numbers, to be exact. The ‘padlock’ is generated using two big prime numbers, creating a ‘public key’ – this is like an open padlock. The ‘private key’ – the unique key that can open the padlock, is also derived from these numbers, but it’s kept secret.

In this system, anyone can use the public key to encrypt a message (or ‘lock the box’), but only the person with the private key can decrypt it (‘open the box’). This is known as public key cryptography and is widely used to secure sensitive data transmission over the internet.

What makes RSA particularly brilliant and durable is that it’s based on the factoring of large prime numbers, a problem that seems simple but is incredibly tough to solve efficiently. This is what gives RSA its security strength.

The RSA algorithm might not be as simple as Caesar’s shift or as tactile as the Enigma Machine’s rotors, but it’s a real powerhouse in the world of cryptography. From sending emails to making bank transactions, RSA works hard in the background, protecting your data like a true superhero. It may not wear a cape, but its impact on our everyday digital life is nothing short of heroic.


In the vast expanse of the digital universe, cryptography stands as a guardian, protecting our precious data from the forces that would misuse it. From the simple Caesar Cipher, which gave the Romans an upper hand, through the Enigma Machine, which kept the world at war on its toes, to the RSA algorithm, which today shields our online lives, cryptography has evolved. It’s a thrilling story of secret codes, brilliant minds, and relentless innovation.

Just as our means of communication have evolved over the centuries, so too have the methods of keeping those communications safe. Each day, we send and receive a multitude of digital messages, often without sparing a thought for the cryptographic magic that keeps our secrets safe. So next time you send an email or make an online transaction, take a moment to appreciate the unsung heroes of cryptography, working tirelessly in the background to keep your digital world secure.

How to stay safe online:

  • Practice Strong Password Hygiene: Use a unique and complex password for each account. A password manager can help generate and store them. In addition, enable two-factor authentication (2FA) whenever available.
  • Invest in Your Safety: Buying the best antivirus for Windows 11 is key for your online security. A high-quality antivirus like Norton, McAfee, or Bitdefender will safeguard your PC from various online threats, including malware, ransomware, and spyware.
  • Be Wary of Phishing Attempts: Be cautious when receiving suspicious communications that ask for personal information. Legitimate businesses will never ask for sensitive details via email or text. Before clicking on any links, ensure the sender's authenticity.
  • Stay Informed. We cover a wide range of cybersecurity topics on our blog. And there are several credible sources offering threat reports and recommendations, such as NIST, CISA, FBI, ENISA, Symantec, Verizon, Cisco, Crowdstrike, and many more.

Happy surfing!

Frequently Asked Questions

Below are the most frequently asked questions.

Why is Cryptography important?

Cryptography is crucial for maintaining privacy, confidentiality, and integrity in the digital world. It helps secure our personal information, financial data, and business secrets from potential threats, thereby ensuring safe and secure communication over the internet.

Is Cryptography hard to understand?

While cryptography involves complex mathematical theories and algorithms, the basic concepts can be understood with some effort. The essence of cryptography is about transforming data into a form that’s unreadable to unauthorized people, and back again.

Can Cryptography be broken?

Technically, any cryptographic system can be broken given enough resources and time. However, many modern encryption algorithms, like RSA, would require such vast computational resources and time (we’re talking about billions of years using current technology) to break that they’re considered practically unbreakable. That said, as technology advances, the science of cryptography must continue to evolve to stay ahead of potential threats.

Author: Tibor Moes

Author: Tibor Moes

Founder & Chief Editor at SoftwareLab

Tibor is a Dutch engineer and entrepreneur. He has tested security software since 2014.

Over the years, he has tested most of the best antivirus software for Windows, Mac, Android, and iOS, as well as many VPN providers.

He uses Norton to protect his devices, CyberGhost for his privacy, and Dashlane for his passwords.

This website is hosted on a Digital Ocean server via Cloudways and is built with DIVI on WordPress.

You can find him on LinkedIn or contact him here.

Security Software

Best Antivirus for Windows 11
Best Antivirus for Mac
Best Antivirus for Android
Best Antivirus for iOS
Best VPN for Windows 11

Cybersecurity articles

Ad Blocker
AES Encryption
Antivirus – How Does it Work
Antivirus – What is it
Antivirus vs Firewall
Antivirus vs Internet Security
API Security
Application Security
Authentication Examples
Biometrics Examples
Certificate Authority (CA)
Cloud Security
Cryptography Examples
Cryptography Types
Cyber Hygiene
Cyber Insurance
Cyber Resilience
Cyber Safety
Cyber Security
Cyber Security Examples
Cyber Security Types
Cyber Threat Intelligence
Dark Web Monitoring
Data Encryption
Data Integrity Examples
Data Loss Prevention (DLP)
Data Privacy
Data Security
Disaster Recovery (DR)
Do Android Phones Need Antivirus
Do Chromebooks Need Antivirus
Do iPhones Need Antivirus
Do Macs Need Antivirus
Does Linux Need Antivirus
Does Windows 10 Need Antivirus
Does Windows 11 Need Antivirus
Email Encryption
Encryption Key
Endpoint Security
False Positives
File Encryption
Firewall – What Does it Do
Firewall Examples
Firewall Types
Heuristic Analysis
How to Clean and Speed up Your PC
HTTPS Examples
Incident Response
Information Security (InfoSec)
Information Security Types
Internet Security
Internet Security Software
Intrusion Detection System (IDS)
Intrusion Detection System Examples
Intrusion Detection System Types
Intrusion Prevention System (IPS)
Intrusion Prevention System Examples
Intrusion Prevention System Types
IoT security
Multi-Factor Authentication (MFA)
Multi-Factor Authentication Examples
Network Security
Network Security Key
Network Security Types
Next-Generation Firewall (NGFW)
Obfuscated Server
Onion over VPN
Parental Controls
Password Examples
Password Manager
Patch Management
Penetration Testing (Pen Testing)
Penetration Testing Types
Proxy Server vs VPN
Public Key Infrastructure (PKI)
Quantum Cryptography
Red Team
Sandbox Environment
Secure Sockets Layer (SSL)
Security Audit
Security Operations Center (SOC)
Security Policy
Security Policy Examples
Software Patching
Software Security
SSL Certificate
SSL Certificate Types
SSL Handshake
Threat Hunting
Threat Intelligence
Threat Modeling
Threat Modeling Examples
Two-Factor Authentication (2FA)
Two-Factor Authentication Examples
Virtual Keyboard
Virtual Private Network (VPN)
VPN Examples
VPN Kill Switch
VPN Protocol
VPN Split Tunneling
VPN Tunnel
VPN Types
Vulnerability Scan
Web Application Firewall (WAF)
White Hat Hacker
Windows Defender
Wireguard vs OpenVPN
Zero Trust Architecture