What is cryptography?

Cryptography is a technique that is often used in cybersecurity to protect information. It relies on algorithms to encode data so that only someone with the correct key can decode it. This key could be a password, a physical key or another type of secret code.

The purpose of encrypting data is to make it difficult for unauthorized individuals to access it, even if they intercept it. Securing this data is an essential part of cybersecurity, and is one of the main techniques to protect data from unauthorized access.

Cryptography can be broadly divided into two categories: symmetric-key and public-key. In symmetric-key, the same secret key is used for both encryption and decryption. The sender and the receiver must share the same key, which can be challenging in situations where the parties have never met.

On the other hand, public-key or asymmetric, involves the use of two keys — a public key and a private key. The public key used to encrypt messages is freely available. The private key, which is kept secret, is used to decrypt the messages. The technique has revolutionized the industry by making it possible for secure communication to take place over insecure networks.

This data security method has been leveraged across a wide variety of industries including:

It has numerous applications in the modern world, most notably in online security. With the rise of e-commerce and online banking, there is a greater need for secure transactions over the internet. It is used to protect the transmission of sensitive data such as credit card numbers, passwords and other personal information.

It's still used in military and intelligence operations. During times of war, it can make the difference between victory and defeat. Governments and militaries use sophisticated encryption techniques to protect their communication and keep their strategies secret.

In the field of digital rights management, it is used to protect digital content such as music, movies and books from unauthorized access and distribution.

Cryptography encompasses a variety of techniques and algorithms. The most common techniques include a secret key, a public key and hash functions.

A secret key is a piece of information or framework used to encrypt and decrypt messages. Each participant in a private communication has access to a shared secret key. The system’s level of security depends on both the strength of the encryption algorithm and the secrecy of the key. The key must be known only to the sender and receiver of the message. If the key is compromised, the security of the system is compromised.

A public key is a large numerical cryptographic key used to scramble data. Unlike a secret key, which is kept private, the public key is shared with everyone in the network. The only way to decrypt a message using one key is to use the second key. This is often used in online banking, email and file-sharing applications.

Hash functions are algorithms that accept inputs of any size and generate what is known as a hash, or a fixed-length output. Hash functions are intended to be one-way, meaning it is difficult or impossible to reverse the process and use the hash to determine the original input. This makes them helpful in verifying a data set has not been tampered with or corrupted. They are also used in digital signatures and to protect passwords.

A career in cryptography can involve various tasks, such as designing and implementing encryption algorithms and protocols, developing software that uses cryptographic techniques, auditing systems for security vulnerabilities or researching new cryptographic algorithms.

As technology becomes more sophisticated, the need for professionals in this area will only continue to grow, which means jobs may become increasingly available. For example, demand for information security analysts is projected to grow by 32% from 2022 to 2032, according to the U.S. Bureau of Labor Statistics.

BLS Occupational Employment Projections, 2022-2032 is published by the U.S. Bureau of Labor Statistics. This data reflects BLS’ projections of national (not local) conditions. These data points are not specific to University of Phoenix students or graduates.

To pursue a career in cryptography, individuals should be comfortable with math and computer programming. For example, to become an information security analyst, a bachelor’s degree in computer science, information technology or a related field is often recommended. Professional certification may also be required.

IT graduate-level programs often teach encryption and cryptography methods. Graduate-level programs can offer advanced courses. They can also give students research opportunities to learn more about specific topics to better prepare for a professional setting.

Many more options are available, such as online courses, boot camps and self-study materials.