Cryptography in Cybersecurity: Definition, Types & Examples

The increasing digitisation worldwide has made security an indispensable aspect of data protection. This is where cryptography and its applications in cybersecurity come into play. 

Cryptography is one of the most trusted and widely used tools for safeguarding IT assets. Almost every business uses cryptography to secure sensitive data and their IT infrastructure. Cryptography is a cybersecurity domain that encrypts or decrypts data through various algorithms at rest and in transit. This blog will discuss the types and applications of cryptography in detail. 

Understanding Cryptography 

Cryptography can be defined as the art and science of concealing information and data in an unreadable format so that only the intended individual can read it. In other words, cryptography is a study to secure communication that allows only the message sender and the intended recipient to view the message’s contents. 

The applications of cryptography have been traced back to the ancient Egyptians. However, the art of coding has reached new heights over the millennia. Modern cryptography combines engineering, advanced computer technology, maths and other disciplines. 

Cryptography creates highly secure and sophisticated cyphers and algorithms for protecting sensitive data in this digital era. 

Cryptography in cybersecurity involves the use of encryption and decryption algorithms. It is used for digital signing, cryptographic key generation, confidential communication, internet browsing, and verification to ensure data privacy. 

Ultimate Goals of Cryptography 

Cryptography is essential in cybersecurity to provide the user and their data with additional protection, ensuring confidentiality and privacy. It protects sensitive data from being compromised or stolen by cybercriminals. 

The four main objectives of cryptography are:

• Confidentiality: Only the intended recipient can access and read the data. Hence, the data remains private. 
• Ensuring data integrity: The encoded data must not be tampered with or modified en route from the sender to the recipient without any traceable marks. 
• Authentication: The receiver and sender can verify each other’s identity and the destination of the information.  
• Non-repudiation: The sender becomes accountable for the messages they send. The latter cannot deny that the message was transmitted – email tracking and digital signatures are some examples of this. 

Cryptography & Its Types

Let’s look at the different types of cryptography in cybersecurity. 

1. Symmetric Key Cryptography/Single Key

In symmetric key cryptography, the same key is used in cryptography to encrypt and decrypt information. The keys used in this kind of encryption should be kept secret by both parties, making them vulnerable to attack from hackers. Symmetric cryptography is often employed to safeguard the local storage of sensitive data on servers or drivers. 

The main drawback of this method is finding a way to securely share the key between the sender and receiver. Advanced Encryption Standard (AES) and Data Encryption Standard (DES) are examples of this method. 

Types of symmetric cryptography 

Often, symmetric encryption is referred to as secret key cryptography. This is because one single private key is used. There are a few forms of this type of cryptography, such as:

• Block cyphers:  This form of cryptography – including the Fiestal cypher – codes and decodes one data block at a time. 
• Stream cyphers: This form works on a single data byte at a time and regularly changes the encryption key. In this method, the keystream can be in tandem with or independent of the message stream. 

2. Asymmetric Key Cryptography/Public Key

Asymmetric key cryptography uses two keys instead of one. This is a more secure cryptography involving the sender and receiver having two private and one public key. The sender uses the receiver’s public key to encrypt the message. On the other hand, the receiver uses the private key to decrypt it. 

This type of cryptography safeguards sensitive data transmission across public networks. As the receiver has access to the private key, they will be the only ones able to read the information. The RSA algorithm is one of the most widely used forms of public key cryptography in cybersecurity. 

Types of Asymmetric Cryptography  

There are various kinds of asymmetric key algorithms, including:

• RSA: It is the basis of key exchanges and digital signatures. Its algorithm is based on the principle of factorisation. 
• Digital Signature Algorithm (DSA): Created by the National Institute of Standards and Technologies, it is the standard for verifying electronic signatures and is built on the modular exponentiation principles. 
• Elliptic Curve Cryptography (ECC): This type of cryptography uses the algebraic structure of elliptic curves for building complex algorithms. It is ideal for electronic devices – such as smartphones – with limited computing power since they don’t need much storage or bandwidth. 
• Identity-based Encryption (IBE): In this algorithm, the receiver doesn’t have to provide the public key to the sender. Instead, the sender uses some known unique identifier – such as email address – to generate a public key to encode the message. A corresponding private key is then generated by a third-party server, which the receiver can access for decrypting the information. 

3. Hash Functions

These are the kind of cryptographic algorithms which don’t use any keys. Instead, they use a hash value – a number with fixed lengths that acts as a unique data identifier – designed based on the length of the plain text information and is employed to encrypt the data. Various operating systems generally use this method for protecting passwords. 

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Cryptographic Techniques in Cybersecurity

Of the several techniques employed for concealing data and files through cryptography, some have been listed below:

• Hashing 

In this method, a data string is converted into a unique string. Irrespective of the data type, this technique will change the data into a unique, irreversible form. Hashing is used for message integrity, password validation, blockchain technology, checking file integrity, etc. 

• Steganography

It is an old technique to conceal data or messages behind non-secret images, data, text or other files. In this method, the secret message is blended with the file, therefore becoming incredibly challenging to detect. 

• Salting 

It is another technique used in hashing to enhance and make them unreadable. Just like adding salt to food improves its taste, this salting technique strengthens the hashing process. A random salt string can be placed on either side of any password to change its hash string. 

Encryption vs Decryption 

Let us understand the concepts of encryption and decryption in cryptography. 

• Encryption

Data encryption in cybersecurity is essential. It refers to the process of using an algorithm to convert binary data from one form to another, accessible only via a specific key. 

An algorithm converts plaintext into ciphertext (or difficult-to-decipher form) for successful encryption. This can only be converted back to plaintext using a cryptographic key. Designing a complex encryption algorithm will help increase security during data transmission and minimise the threat of data being compromised. There are various types of encryption in cybersecurity, the two prevalent being symmetric and asymmetric encryption.

• Decryption 

Decryption is used for reversing encryption. A user can decrypt sensitive encrypted data using a cryptographic key. The various types of decryption include RSA, Triple DES, AES, Blowfish and Twofish. 

Depending on the robustness and the complexity of the algorithm, both encryption and decryption will help optimise security and safeguard sensitive data. 

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Applications of Cryptography in Daily Life

The use of cryptography in cybersecurity is vital to protect confidential and sensitive data. Here are some of the top applications of cryptography. 

1. Digital currency 

A well-known application of cryptography is digital currency, where cryptocurrencies are traded over the internet. Digital currencies are growing popular due to the cashless economies. Unregulated by banks or governments, cryptocurrencies such as Bitcoin, Ripple, and Ethereum are our future. 

2. E-commerce 

On e-commerce websites, we can buy and make payments online. These transactions are encrypted and, hence, cannot be tampered with by any third party. All e-commerce platforms have specific passwords for each user so no hacker can access their data. 

3. Military operations 

Military operations have been making use of cryptography for a very long time. Military encryption devices have been used for encrypting military communication channels. They convert the real communication characters so that enemies aren’t able to decrypt them.  

Cryptographic Attacks – A Study of Their Types

Although highly sophisticated, cryptography is vulnerable to threats. In case the key is compromised, it is easily possible for a third party to crack the code and get access to the protected data. Here are some potential attacks that might happen. 

• Weak keys: Keys are a collection of random numbers with a particular encryption algorithm for altering and disguising data. This makes it incomprehensible to others. Longer keys have more numbers, thereby making it much trickier to crack. Hence, it is better for the protection of data. 
• Reusing keys for various purposes: Every key must be unique, like passwords. Employing the same key on multiple systems reduces the ability of cryptography to protect data. 
• Not using keys properly: The keys must be used correctly. When keys are incorrectly used, hackers can easily access sensitive data. 
• Insider attacks: Keys could be compromised by people who can access them – like an employee. Sometimes, people on the inside sell keys for criminal purposes. 
• Not changing the keys: Updating the keys regularly is essential to keep sensitive data secure. 
• Forgetting about the backup: There must be a backup for the keys. If they become faulty, the sensitive data they protect will become inaccessible. 
• Not storing the keys carefully: A hacker will always try to find the keys. It is necessary to store the keys securely where they are not easily accessible. If not, it could lead to sensitive data being compromised. 

Some cryptography attacks are designed to break through encryptions to find the right key. Here are some of them:

• Brute force attacks: These are broad attacks that try to guess the private keys with the known algorithm randomly. 
• Ciphertext-only attacks: These types of attacks are where a third party intercepts the encrypted message (not the plaintext). They try to work out the key, decrypt the data, and finally, the plaintext. 
• Chosen plaintext attack: In this attack, the third party selects the plaintext for a corresponding ciphertext and starts working on the encryption key. 
• Chosen ciphertext attack: The opposite of the previous type, the cybercriminals analyse a part of the ciphertext against the corresponding plaintext to discover the key. 
• Algorithm attack: These are attacks where cybercriminals analyse the algorithms to work out the encryption key. 

Ways to Minimise Risks Associated with Cryptography

There are some ways by which organisations can try to lower the possibility of cryptographic attacks. They are:

• Make sure that the algorithms and keys are updated regularly. 
• Use one specific key for one purpose. 
• Protect your cryptographic keys using stronger KEKs (key-encryption-keys)
• Encrypt all your sensitive information. 
• Employ hardware security models for managing and protecting keys. 
• Create unique, vital keys for every encryption. 

Conclusion

Storing and transferring data securely is paramount today, whether for governments, organisations or private individuals. Cryptography in cybersecurity has become a battleground for computer scientists and mathematicians, and its widespread adoption has turned it into a high-stakes profession. 

It is necessary to ensure confidentiality in conversations and transactions. If you are interested in computer networks, building a career in cryptography can be a good choice. Explore the exciting job opportunities and begin this exciting journey today with a relevant cybersecurity course.