Understanding Cryptography: What It Is and How It’s Used

Written by: University of Tulsa • Apr 13, 2026

A cybersecurity professional works at a desk with several monitors.

Cryptography has existed for thousands of years. For example, many experts believe ancient Egyptian hieroglyphics were created as a secret code that was known to only a few people. And when Julius Caesar grew wary of his messengers around 50 B.C., he developed a cipher, a system for encrypting and decrypting messages, that allowed him to communicate safely with his generals on the battlefield.

Today’s cryptography uses advanced technologies to protect sensitive information. Understanding cryptography allows cybersecurity professionals in all types of organizations to better secure their organization’s data. Earning an advanced degree can help cybersecurity specialists gain the knowledge and skills they need to succeed in the field.

What Is Cryptography?

Cryptography is a method used to protect data by converting it into unreadable formats, rendering it incomprehensible to humans without the appropriate keys. Modern cryptography relies on engineering concepts, software, cryptographic algorithms (also known as ciphers), and mathematical concepts to encrypt and decrypt data. It also uses cryptography techniques like digital signatures to verify a sender’s identity.

Understanding cryptography and practicing it using modern tools has four primary aims:

Confidentiality: Confidentiality is maintained when only individuals with proper authorization can access transmitted information, with the data remaining protected from unauthorized access throughout its entire life cycle.
Data Integrity: Data integrity refers to the accuracy, legitimacy, and consistency of information within a system. To have integrity, the information must come from a trusted source and must not have been tampered with.
Authentication: Authentication is a process in which software is used to verify a user’s identity before granting them access to the data in a system. When a user fails authentication, they can’t access the resources in the system.
Nonrepudiation: Nonrepudiation is a service enabled by technology that ensures the integrity and origin of data through third-party verification and validation.

Everyday Examples of Cryptography

While cryptography plays a vital role in cybersecurity, cybersecurity professionals are not the only ones who encounter it in their everyday lives. Cryptography factors into many people’s day-to-day lives in these use cases and more. Technological advancements, such as the growth of 5G, bring new security risks and cybersecurity vulnerabilities that individuals and companies will need to address.

Creating Secure Lines of Communication

Companies often use cryptography protocols to create more secure lines of communication. For example, messaging applications often use end-to-end encryption (E2EE) to ensure that only the sender and their intended recipient can read the message.

Cryptography also helps create secure connections between web browsers and servers, keeping channels private and preventing access by bad actors.

Ensuring the Integrity and Security of Data

Companies and organizations typically store tremendous amounts of data about both their internal operations and their audience. When this information is not secure, the organization puts itself and the people who trust it at risk. When a data breach occurs, this trust erodes.

Different encryption methods keep data both secure and illegible to any bad actor who may access it. For instance, when an algorithm turns plaintext into ciphertext, an unauthorized user would not be able to decrypt any sensitive data without an encryption key.

Authenticating Information

A common use case for cryptography is digital signatures. Senders can add digital signatures to documents, which can only be generated by a private key. From there, the recipient can use the sender’s public key to verify that signature.

This process ensures that no bad actors have tampered with any information received in this transmission. While the process creates additional privacy for confidential information, it also helps ensure that the information is accurate and received as intended.

Types of Cryptography and Their Algorithms

Understanding cryptography requires knowing about the different types, each of which serves different purposes. The primary types of cryptography are symmetric key cryptography, asymmetric key cryptography, hash functions, and post-quantum cryptography.

Symmetric Key Cryptography

This type of cryptography entails using a single key. Both the sender and receiver of a transmission use the same key to encrypt and decrypt the data. Two types of symmetric key cryptography are stream cipher algorithms, which encrypt text one bit at a time, and block cipher algorithms, which encrypt text a block at a time. Examples of block cipher algorithms include the Data Encryption Standard (DES) and the Advanced Encryption Standard (AES).

Asymmetric Key Cryptography

Like symmetric key cryptography, keys play an important role in asymmetric key cryptography. The primary difference between the two is that symmetric key cryptography uses a single key, while asymmetric key cryptography uses a pair of keys. One key, the public key, encrypts the data, while the other key, the private key, decrypts it. RSA and elliptic curve cryptography (ECC) are examples of asymmetric key cryptography algorithms. Digital signatures also use asymmetric key cryptography pairs to authenticate data.

Hash Functions

A hash function is a one-way method that changes data into a hash value. Hash functions are typically used for password storage. However, instead of storing actual passwords, hash functions in applications store the hash values of passwords to reduce the likelihood that a hacker will retrieve users’ actual passwords.

Post-Quantum Cryptography

Post-quantum cryptography (PQC) is a newer type of cryptography that emerged with the rise of quantum computing. A quantum computer is capable of making calculations that a conventional computer would be unable to make. As a result, a quantum computer may be able to break standard encryption methods. The goal of post-quantum cryptography is to develop new encryption methods that resist these capabilities.

Understanding Cryptography and How It’s Used

Cryptography plays a crucial role in safeguarding sensitive information, making it indispensable for ensuring the security of communication channels such as email, online portals, and web and mobile phone applications. By employing cryptographic techniques, data security applications help to protect various everyday transactions, ranging from file sharing within business networks to online apps used for banking or shopping.

The scope of cryptography extends to multiple domains:

Military and Defense: This sector uses military-grade encryption to safeguard classified information from interpretation by adversaries, ensuring the integrity and confidentiality of sensitive data.
Health Care: Maintaining patient medical records securely is of utmost importance to protect individuals’ privacy. Cryptography ensures that medical information remains confidential and inaccessible to unauthorized individuals.
Entertainment: Cryptography plays a significant role in digital rights management, preventing the unauthorized copying and distribution of movies and music. This helps protect intellectual property rights and combat piracy.
Supply Chain: Cryptography techniques enable vendors and buyers to verify the authenticity of products. By employing cryptographic measures, the integrity of the supply chain can be maintained, ensuring that products are genuine and free from tampering.
Government Communications: Encryption technology is used to safeguard agency-to-agency communications and citizen portals, helping to ensure the nation’s security and protecting the privacy of citizens. By employing strong encryption algorithms, government agencies help keep sensitive government information confidential and protected from unauthorized access.

While cryptography is effective, cybercriminals continuously evolve their tactics to find new ways to break into systems with sensitive data. Cybersecurity professionals must use advanced encryption technologies to stay ahead of potential threats.

Learn How to Fight Cybercrime with Cryptography

Cybersecurity professionals need to employ complex modern encryption techniques to counter the increasingly sophisticated strategies employed by cybercriminals. This makes understanding cryptography an essential aspect of modern cybersecurity.

Corporations and other organizations are increasingly seeking skilled and knowledgeable professionals who can safeguard their valuable data. Pursuing a master’s in cybersecurity program with system security and cryptography in its curriculum can open up a world of career opportunities.

Explore how the online Master of Science in Cyber Security program at The University of Tulsa can help equip you with the skills and knowledge you need to meet modern cybersecurity demands.

Recommended Readings

Preparing for a Cybersecurity Career: Insights From Justin Miller, MA, MS

Visualizing the ROI of a Cybersecurity Degree

Chief Information Security Officer: Job Description and Salary

Sources:

Amazon Web Services, “What Is Cryptography?”

Entrust, “Who Should We Thank for Modern Cryptography? The Egyptian Monks.”

EPSNews, “Utilizing Cryptography in Supply Chain and Procurement”

Fortinet, “What Is Cryptography?”

Fortra, “How DRM Encryption Protects Video Content”

IBM, “Cryptography Use Cases: From Secure Communication to Data Security”

Kingston Technology, “Enterprise-Grade versus Military-Grade Security: What’s the Difference?”