What is Cryptography?

In today’s digital world, data flows ceaselessly through systems and networks from every industry and sector. With the global creation of data estimated to reach 180 zettabytes by 2025, according to Statista, the protection of digital information has become paramount to securing our way of life and future.

Cybersecurity professionals use cryptography, the art and science of securing communication and data, to prevent third-party individuals or online attackers from reading digital information. For example, when you use a credit card for an online payment or an email provider like Gmail or Outlook, cryptography is used to secure the transaction or message.

Understanding how cryptography works is helpful to those considering careers in cybersecurity and fighting online threats. Read on to find out more about cryptography, its principles, types, and how you can learn cybersecurity.

What is Cryptography?

Cryptography, at its core, involves the application of mathematical principles and algorithms to encrypt and decrypt information. In the encryption process, plaintext is converted into ciphertext, which is an unintelligible form that cannot be read by unauthorized parties. The reverse process of converting ciphertext back to plaintext is decryption.

Cryptography uses keys, which are strings of characters that alter data to make it seem random in an encryption algorithm. Similar to its physical counterpart, a key in cryptography locks or encrypts data so that it can only be decrypted by someone who has the proper key. The cryptography process ensures:

Confidentiality: Encrypted messages are protected from unauthorized access through cryptography. Even if a cybercriminal intercepts it, without the proper key, the information remains secure.

Integrity: Cryptography maintains the integrity of data by detecting any alterations or tampering. If the data is changed in transit, the decryption process will fail, alerting the recipient of potential foul play.

Authentication: By using digital signatures and certificates, cryptography confirms the identity of the sender or the integrity of a message. This is crucial in the digital world, where trust is built on verifying the source of information. One common method of authentication is the Diffie-Hellman key exchange. This method allows two parties to create a shared secret key over an insecure channel. Public values are generated from private keys using a public prime and a base. Each party calculates an independent secret key based on these public values, which makes it possible to communicate securely.

Non-repudiation: Non-repudiation ensures that a sender cannot deny sending a message, and a recipient cannot deny receiving it. Digital signatures play a pivotal role in achieving non-repudiation.

Despite its wide use today, cryptography is not a new practice. In ancient Egypt, Mesopotamia, Greece, and Rome, evidence of cryptography can be found. For example, the Caesar Cipher was a simple encryption technique used by Julius Caesar to share secret messages to his allies. During World War II, the Enigma machine was used to encrypt communications. When the Enigma code was broken, the Allies were able to read German messages and learn about plans. Modern cryptography blends age-old techniques and innovative approaches to create robust systems for securing digital data.

Applications of Cryptography

There are many real-world applications for cryptography, including securing online banking transactions, protecting personal emails, shielding sensitive government communications, and ensuring secure e-commerce transactions. Cryptography also serves a variety of other crucial functions, including:

Data Encryption: Without the decryption key, unauthorized parties cannot comprehend encrypted data, even if they gain access to it.

Digital Signatures: A digital signature verifies the authenticity and integrity of an electronic document or message.

Authentication: In various online interactions, cryptography is used to establish the identity of users or entities.

Blockchain Technology: Unlike other distributed ledger systems, blockchain uses cryptographic principles to protect transactions.

Cryptography has a menagerie of uses depending on the context of the application.

Types of Cryptography

In today’s cybersecurity industry, cryptography can be broadly categorized into three types:

Symmetric Encryption: Symmetric encryption or secret-key cryptography uses a single key to both encrypt and decrypt data. It's like having a single secret key to lock and unlock a door. Symmetric encryption is used more for storage and cannot be used for ensuring the integrity and/or authenticity of data.

Asymmetric Encryption: Asymmetric encryption uses a pair of keys: a public key to encrypt the data and a private key to decrypt it. The public key can be shared openly, but the private key must be kept secret. The cryptography type focuses on preserving the integrity and/or authenticity of data.

Hashing or Hash Functions: Hashing takes an input or “message” and returns a fixed-length string of characters, which is typically a hash value. Hash functions are one-way functions, making it extremely difficult to reverse-engineer the original message from the hash. One common use for hash functions is password storage. If the stored information is compromised, the attackers will not have access to the plaintext passwords because hashes do not preserve the original data. Hashes are also commonly used for checking integrity of files or identifying known malicious files.

Cryptographic Algorithms

The encryption, decryption, and hashing of data are implemented using a variety of cryptographic algorithms. Here are three prominent cryptographic algorithms:

Advanced Encryption Standard (AES): In terms of efficiency and security, AES is one of the most commonly used symmetric encryption algorithms. Due to its variable-length key, it can be used for a wide variety of encryption purposes.

Rivest–Shamir–Adleman (RSA): An RSA algorithm uses a pair of keys for encryption and decryption: a public key for encryption and a private key for decryption. The algorithm is fundamental to secure communication.

Secure Hash Algorithm-2 (SHA-2): Data integrity can be verified using the SHA-2 cryptographic hash function, which produces a fixed-length output.

As technologies continue to evolve, so do cryptography and the algorithms.

Why Learn About Cryptography

Whether you work in cybersecurity, programming, data science, or simply want to learn how to communicate and protect your data, learning about the uses and types of cryptography provides a wide range of benefits, including:

Career Opportunities: Cryptography underpins some core principles and technologies in cybersecurity and data analytics, ensuring the confidentiality, integrity, and authenticity of data and communications. Roles like information security analyst, penetration tester, and security architect require an understanding of cryptography. CyberSeek reports that more than 600,000 cyber jobs are available in the U.S., with nearly 30,000 designated for entry-level workers. With cybersecurity professionals in demand, knowing about the uses of cryptography can unlock career opportunities.

Understanding Modern Technologies: Various modern technologies rely on cryptography, including blockchain technology, secure payment systems, digital identities, secure cloud computing, and even web browsers. To understand how these technologies work and maintain security, you need to know the basics of cryptography.

Compliance and Regulations: Compliance standards and regulations related to data security are required by many industries. A grasp of cryptography is crucial for adhering to these regulations and ensuring compliance within your organization.

Research and Innovation: Cryptography is an exciting field for research and innovation with many open problems and opportunities for breakthroughs. Recently, an area of focus for researchers has been quantum computers. Quantum computers deal with mathematical problems that are intractable to conventional computers by exploiting quantum mechanical principles. In the future, quantum computers may have the potential to break many of the public-key cryptosystems currently in use. Knowing about cryptography fundamentals can help you understand cybersecurity industry changes.

Ultimately, learning cryptography helps individuals navigate the evolving landscape of cybersecurity, protect sensitive information, and contribute to technological advances.

How To Learn Cybersecurity

There are many ways to learn more about the role of cryptography in cybersecurity, such as self-paced courses and traditional degree programs. For those looking to learn tech skills and gain the fundamental knowledge of cryptography needed for cybersecurity roles, online bootcamps like the programs by Fullstack Academy can help you. The Fullstack Academy Cybersecurity Analytics Bootcamp offers:

• Full-time and part-time schedule options;

• Live online training taught by industry-experienced professionals;

• An immersive, beginner-friendly curriculum that gives you hands-on experience using real-world scenarios;

• Career success support to help you land a job in cybersecurity;

• And, more.

If you’re ready to take the next step in your career journey and gain cryptography skills, apply today to the Fullstack Academy Cybersecurity Analytics Bootcamp.