Cybersecurity and Cryptography: Their Eternal Relationship

By Dr. Andre Slonopas  |  02/03/2025

With the rapid, unbridled growth of technology and the internet, people, companies, and governments deeply rely on digital systems for storing, processing, and transmitting sensitive information.

Effective cybersecurity protects the confidentiality, integrity, and authenticity of sensitive data. From personal identification numbers (PINs) to sensitive financial data and national security secrets, the need for keeping information confidential and secure has utmost priority in today's digital world.

Cyber threats – from data breaches and ransomware attacks to phishing scams – are a constant danger. Cryptography, however, plays a vital role in ensuring that data remains secure.

What Is Cryptography?

In cybersecurity, cryptography uses mathematical algorithms (mathematical formulas) to provide security for digital communications. Cryptography changes data into an encrypted form, accessible to a lone keyholder or any other authorized party. This encryption keeps data protected, even against sophisticated cyber-attacks.

The role of cryptography surpasses the mere protection of information. It underpins secure online transactions, authenticates protocols, and strengthens the communication channels of everything from a smartphone to global financial networks. With the growth of cyber threats, robust cryptographic practices have also grown, acting as a shield against both known and emerging perils.

Why Is Cryptography Important?

Personal information, financial details, and intellectual property are all types of sensitive data that form the backbone of our society. A big challenge in cybersecurity is the protection of sensitive information against unauthorized access and manipulation.

Over time, cyber threats have grown in sophistication. Consequently, organizations need to adapt robust cryptographic techniques throughout the data lifecycle.

The Core Principles of Cryptography

Cryptography relies on four basic principles:

• Confidentiality
• Integrity
• Authentication
• Non-repudiation

All four principles act as guidelines for cryptographic algorithms and enable secure communications in our ever-digitizing world.

Confidentiality

In cryptography, confidentiality ensures that information is kept private and is only available to authorized users with the right type of key. Cryptographic techniques entail symmetric key cryptography and asymmetric encryption to reach this goal. Symmetric encryption, based on the use of the same key for both encryption and decryption, is usually used for the encryption of data due to its speed and efficiency.

The Advanced Encryption Standard (AES) is a widely adopted encryption algorithm of symmetric key cryptography. Symmetric key cryptography protects data packets, both in storage and in transit.

On the other hand, asymmetric encryption uses a public key and its corresponding private key in securing communications. For instance, online transactions use protocols such as Transport Layer Security (TLS).

Integrity

Data integrity means that no alteration happens with data while it is in transmission or storage. Cryptographic hash functions, like Secure Hash Algorithm-256 (SHA-256), are in wide use for generating unique hash values of the data so that data authenticity can be verified.

If any modification happens to the data requiring protection, the hash value changes and the change signals potential tampering. The applications of cryptographic hash functions include password storage, financial transaction security, and the assurance of the validity of digital certificates.

Authentication

Authentication establishes the identity of the data’s sender and receiver in any secure communication. Some of the important cryptographic techniques that perform authentication include public key cryptography and digital signatures.

The digital signature – created with the private key of the sender and with its authenticity checked by a public key – guarantees the origin and authenticity of the data. This technique has broad applications in secure data exchanges where sensitive data needs protection, such as communications or online transactions.

There are various mechanisms for authentication. They use encryption protocols and algorithms for digital signatures to ensure that encrypted data is only available to the correct recipient.

Non-Repudiation

Non-repudiation implies that neither the sender or the receiver can refute an action and is held accountable. The cryptographic system is designed to provide non-repudiation by implementing digital signatures and asymmetric encryption.

Since the cryptographic algorithm involves public and private keys, the sender cannot repudiate a previously signed message, and the recipient cannot forge the sender’s signature. Non-repudiation is particularly important for sensitive data involved in any legal contract or financial transaction.

Why Is Cryptography Necessary?

Personal information, financial details, and intellectual property are all types of sensitive data that form the backbone of modern digital ecosystems. A big challenge in cybersecurity is the protection of sensitive information against unauthorized access and manipulation.

Over time, cyber threats have grown in sophistication. Consequently, organizations need to adapt robust cryptographic techniques throughout the data lifecycle.

Types of Cryptographic Algorithms and Their Role in Cybersecurity

Cryptographic algorithms ensure security and have different roles in data protection. They can be divided into three categories:

• Block and stream ciphers
• Hash functions
• Key derivation functions

Block and Stream Ciphers

Block ciphers, such as AES, encrypt information in fixed-size blocks and are highly efficient for securing large quantities of data. AES has become the de facto encryption standard used in full-disk encryption applications for the protection of data at rest.

On the contrary, stream ciphers, including Rivest Cipher 4 (RC4), encrypt data in either one bit or a byte at a time. Stream ciphers are suitable for applications concerning real-time communication applications that involve voice or video streaming.

Hash Functions

The cryptographic hash function is a type of algorithm that converts inputted data into a unique, fixed-length hash value. Even a single change to the original data results in a different hash value.

Hash functions are used for password storage, integrity verification of downloaded files, and the creation of digital signatures.

Key Derivation Functions

Key derivation functions (KDFs) are algorithms used to harden a password or generate a cryptographic key from a user-provided input. Examples of KDFs include:

• Password-Based Key Derivation Function 2 (PBKDF2)
• Bcrypt

KDFs are less vulnerable to brute-force attacks and dictionary attacks. They can be used for the storage of passwords and generation of encryption keys within secure systems.

Cryptographic Methods for Data Protection

There are various cryptographic methods to ensure that data remains secure. These solutions include:

• Encryption and decryption techniques
• Digital signatures
• Hash functions
• Key management and secure protocols
• Secret key cryptography
• Public key cryptography

Encryption and Decryption Techniques

To encrypt data at one end and decrypt it at the other end, the sender and the receiver can use symmetrical cryptography or asymmetric cryptography. Both require the use of a private key or a public key.

Symmetrical cryptography uses the same symmetric key to encrypt data or decrypt data. It is very efficient for the bulk transfer of sensitive information, either for data stored within a computer or in raw form. The most notable example of this approach is the AES algorithm.

Asymmetric cryptography depends on a public key for encryption and a private key for decryption, making communication secure without sharing any secret keys. It is the basis for digital certificates, public key encryption, and asymmetric key algorithms in the secure exchanges of data.

Digital Signatures and Data Integrity

In cryptography, digital signatures are created with a sender's key that is kept private to protect sensitive data and also verified by a public key to ensure data integrity and authenticity. The data can only be verified by an intended party and is difficult to alter.

Hashing

Hash functions such as SHA-256 allow a digital fingerprint to be created, and systems use that fingerprint to identify encoded data that may have undergone unauthorized changes. Hashing plays an important part in ensuring data integrity, the safe storage and verification of password authenticity, and the validity of digital certificates.

Key Management and Secure Protocols

Key management is effective in safeguarding encryption keys and enabling authorized users to access data that has been encrypted. TLS and virtual private network (VPN) protocols are used to maintain the security of data packets during transmission.

Secret Key Cryptography

Secret key cryptography (also known as symmetric encryption) is one of the most deployed cryptographic techniques in cybersecurity. It leverages the same secret key to encrypt and decrypt data, and it is an uncomplicated but effective way of securing data.

Through this technique, plain text is transformed into encrypted data by the sender. The receiver uses the same key to decrypt the data.

Since the same key is used by both sender and receiver, data confidentiality is maintained. If an unauthorized user gains access to the key, then that user could decrypt the data.

Among the very first symmetric encryption algorithms that were developed to protect sensitive information was the Data Encryption Standard (DES). However, DES is now considered obsolete because it uses a short key that is susceptible to brute-force attacks enabled by advances in quantum computing and cryptanalysis.

The need for addressing the shortcomings of DES gave birth to the Advanced Encryption Standard (AES). AES has become the golden standard of cryptography because it offers robust security due to variable key lengths, such as 128-, 192-, or 256-bit keys.

Due to its effectiveness and efficiency, AES is also important for the encryption of financial transactions, data storage, and virtual private networks.

The Triple Data Encryption Standard (3DES) is an extension of DES. It makes use of the block cipher algorithm to keep data confidential and runs on a block of data three times with different keys. While it improves on security compared to DES, 3DES is slower and less efficient than AES.

Symmetric encryption is very fast. As a result, large sets of information can be encrypted quickly, which is particularly useful for real-time secure communications.

Symmetric encryption also requires a low amount of computation. It is helpful for environments when computing resources are meager and very limited.

Symmetric encryption also has its limitations when it comes to keeping data secure. The major problem is key distribution.

Secure key exchange methods should ensure that only the correct decryption key is obtained by the sender or receiver. Otherwise, that key would render an entire communication prone to risk in case any part of it is divulged to the wrong user.

Public Key Cryptography

Public key cryptography – also known as asymmetric cryptography – employs a public key used for asymmetrically encrypting plaintext or data. It also uses a key that is kept private and reverse-encrypts cyphertext for the receiver. This separation of keys provides an alternative to sharing a single encryption key, allowing key exchanges to be handled more securely.

In public key cryptography, only the intended recipient with the appropriate decryption key can access encrypted data. For data encrypted via a recipient's public key, that data can only be decrypted with a private key to keep it confidential.

Public key cryptography depends on a number of complex encryption algorithms. The Rivest-Shamir-Adleman (RSA) algorithm is one of the earliest and most used algorithms in cryptography. It is based on the mathematical problem of factoring large prime numbers.

Another advanced algorithm involves Elliptic Curve Cryptography (ECC), which offers similar security to RSA but uses smaller key sizes, so that it is more efficient for resource-constrained devices. These algorithms have a key role in data encryption, digital signatures, and secure key exchanges.

Asymmetric cryptography provides better security in cases of exchange of keys or user authenticity than symmetric cryptography. However, it is computatively intensive and slower than symmetric cryptography.

Public key cryptography is unsuitable for large amounts of data encryption. Many cybersecurity specialists use a hybrid approach by first using public keys, then private keys to combining the strengths of the two different systems.

Future Challenges in the Protection of Sensitive Data

Sensitive information, either in storage or during transmission or processing, often undergoes certain risks. Cybercriminals exploit any security gaps they find and gain unauthorized access to computer systems. The resulting breach results in the loss of data and brings financial losses to an organization.

To protect data at every stage, organizations should implement cryptography for strong encryption techniques, good security management, and security protocols. Other cybersecurity threats such as quantum computing might soon make traditional cryptographic algorithms obsolete. As a result, cybersecurity professionals will need to work harder in the future to further safeguard communication and storage systems.

Cybersecurity Degrees at American Military University

For students interested in learning about cryptography concepts and other aspects of cybersecurity, American Military University (AMU) offers several degree programs:

• An online associate of science in cybersecurity
• An online bachelor of science in cybersecurity
• An online master of science in cybersecurity studies

Courses in these programs include hardening operating systems, red and blue team security, and law, privacy, and digital data. Other courses involve topics such as cyber warfare, digital forensics, biometrics, cybercrime, and information assurance.

For more information on AMU’s cybersecurity programs, visit our information technology degree program page.