What is cryptography? Cryptography types explained

What is cryptography

Cryptography is the process of coding information to secure it and prevent unauthorized access. It involves using complex mathematical algorithms to transform the original data (i.e., plaintext) into a format known as ciphertext. The ciphertext is encrypted and can’t be read without a decryption key.

Cryptography isn’t a new concept — sophisticated methods of hiding information have existed in various cultures for several millennia. For example, cryptographic methods can be traced back to ancient Egyptians and their use of hieroglyphics to protect sacred texts.

In modern times, cryptography is a crucial component of secure communications. Cryptographic technology has evolved over the last few decades, leading to the development of advanced techniques, systems, and protocols to keep data safe. It is now largely adopted by many businesses and organizations, including government agencies.

How does cryptography work?

Cryptography uses complex mathematical algorithms to create a secure means of communication. In most cases, the cryptographic process involves scrambling the original (input) data to make it unreadable to anyone who doesn’t have authorization to access it. The text becomes unreadable unless you have a decryption key that transforms it back into its readable form.

One vital element of secure cryptography is the complexity of the algorithm used in the scrambling process. The more complex the algorithm, the stronger the encryption — and the harder it becomes for hackers to access the information.

There are three main types of cryptography. Let’s look at how they work, their differences, and how they’re used.

Types of cryptography

Modern cryptography can be grouped into three different types: symmetric key, asymmetric key, and public key encryption. Let’s look at each of these cryptography types in more detail.

Symmetric key cryptography

Symmetric key cryptography, also known as secret key encryption, uses a single key for the whole process. The sender and receiver use this key to encrypt and decrypt a message they want to protect, meaning the key has to be securely shared between them.

This part of the process poses a potential vulnerability — having to exchange the key may mean cybercriminals have more opportunities to steal it and access the message. Because of this characteristic, symmetric key cryptography isn’t used as widely as asymmetric key encryption.

Asymmetric key cryptography

Asymmetric key cryptography, or public key encryption, is often considered a more secure way to protect sensitive information. Asymmetric encryption involves using two keys – a private and a public one – to encrypt and decrypt data. Both keys are related — you need one to encrypt information and the other to decrypt it.

First, data is encrypted using the recipient’s public key, widely available on the network. To decrypt the data, the recipient needs to use a corresponding private key, which is only known to them. That way, only the intended recipient can decrypt the message — as long as their private key is kept safe.

Unlike symmetric cryptography, asymmetric encryption doesn’t require users to exchange secret keys, meaning there’s a smaller chance a cybercriminal may steal them during transmission.

Hash functions

Hash functions are cryptographic algorithms used for protecting sensitive information and its integrity. A hash function encrypts the information using a complex mathematical algorithm and produces a unique string of characters corresponding to the data. This string is known as a hash value, which is unique for each message. Even the slightest change in the input would result in a different value.

Hashing is particularly effective in authentication and ensuring the integrity of the data. For example, it may be used to securely store passwords in databases or to check the authenticity of digital signatures.

Unlike symmetric and asymmetric encryption, hashing is a one-way process. You can produce a unique hash for input data, but decoding the data behind a hash value is impossible. That said, some hackers may launch brute-force and dictionary attacks to see if they can produce the same hash value for input. That’s why it’s important to use strong cryptographic hash functions (and even additional measures like password salting).

Both hashing and encryption offer excellent security but are used in different ways. While encryption scrambles your data to make it unreadable, hashing turns your information into a unique code that can’t be reverted. Here’s more on hashing vs. encryption and how these cryptography types differ.

The importance of cryptography

Cryptography is important for many reasons, particularly when it comes to information security.

• Confidentiality. Cryptography protects confidential information, even if hackers manage to intercept it. Cybercriminals are always coming up with new, sophisticated ways to steal user information for further malicious attacks. By encrypting online traffic, passwords, and other sensitive data, organizations make it much harder for hackers to successfully launch various types of cyberattacks. Even if cybercriminals manage to get hold of this information, they can’t read it without a decryption key.
• Data integrity. Cryptography also helps ensure data integrity. For example, by using the hash function for digital signatures, companies can ensure that important data hasn’t been tampered with. With most of our important life decisions now happening online (e.g., buying a house or taking out a business loan), confirming the integrity of messages is incredibly important.
• Authentication. Cryptography helps organizations verify the authenticity of data, messages, and other information. By using cryptography techniques, companies can confirm the identity of those sending and receiving messages, which helps improve the digital security of employees, customers, and entire organizations.
• Non-repudiation. Cryptography also provides evidence of a sender’s approval and may help prevent false claims. For example, digital signatures ensure that a sender can’t claim that a contract, document, or message is fraudulent — the digital signature shows the sender themselves approved and signed the document.

Many people don’t realize how important cryptography is and how it can protect you as you go about your business online. That’s why learning about cryptography is so important. The more you know about this technology, the better you’re able to use it to your advantage.

Cryptography in cybersecurity

Cryptography plays a crucial role in cybersecurity. With everyone constantly exchanging information online, ensuring data authenticity, integrity, and confidentiality is paramount. That’s why cryptography is an important cybersecurity tool used by various organizations globally.

In cybersecurity, cryptography is most closely linked to encryption. Using cryptographic methods, encryption scrambles data into a format that can’t be read without the right decryption key. This process safeguards sensitive information and helps prevent cyberattacks, data breaches, and unauthorized access. Here are some examples of cryptography use in cybersecurity:

• Secure communication. Cryptography encrypts online messages to protect against eavesdropping (e.g., WhatsApp).
• Digital signatures. Cryptography techniques like hashing are used to authenticate digital signatures and prevent unauthorized actions.
• Password protection. Hashing is also used to secure passwords (e.g., encrypted password managers).
• Blockchain security. Cryptography allows users to securely manage their cryptocurrencies and complete transactions.
• Email security. Email providers use industry-standard encryption to secure emails and minimize the chances of a cyberattack.

Cryptography and VPNs

Cryptography and network security go hand in hand. A VPN (virtual private network) is a network security tool that secures your online traffic and hides your IP address. Cryptography is one of the vital features of a VPN — that’s how it secures your internet connection.

A VPN uses cryptographic techniques to encrypt the online traffic traveling to and from your device, making it unreadable to snoopers and hackers. Even if these malicious parties manage to intercept your connection, your online traffic will look like gibberish, and they won’t be able to use it for malicious purposes. That’s how VPNs protect you from eavesdroppers, internet service providers, and anyone else who may want to look up your online activity.

Examples of cryptography

Cryptography is used in several different ways and for various digital security purposes. Let’s look at some examples of cryptography protocols and how they’re used.

Symmetric encryption protocols: AES, Triple DES, Blowfish

Generally, symmetric cryptography is used when bulk encryption is needed. Encrypting entire databases (e.g., e-commerce, healthcare, or financial) or online traffic would normally be the work of symmetric encryption. For example, AES (Advanced Encryption Standard) is a well-known symmetric encryption protocol used for encrypting and securely transferring data by VPNs and HTTPS.

Blowfish, a symmetric block cipher, is commonly used for file encryption. You’ll often find it as one of the security features in file storage and encryption software designed to protect files from unauthorized access.

Asymmetric encryption protocols: RSA, Diffie-Hellman key exchange

Asymmetric encryption is typically considered stronger than symmetric. This highly robust cryptography type is often used to secure crypto transactions, digital signatures, email encryption, and file transfers.

Some examples of asymmetric encryption protocols are RSA and Diffie-Hellman key exchange. RSA encryption is used for secure digital communications, email encryption, and digital signatures. It’s also a common security measure for protecting cryptocurrency transactions.

The Diffie-Hellman key exchange protocol is designed to secure communications over an insecure channel (e.g., public Wi-Fi networks). Its purpose is to establish a shared secret key between two parties, which doesn’t need to be sent over the network.

Hashing encryption protocols: SHA-1 and SHA-2

Hashing is typically used for checking the authenticity of a file or message. Each hash value produced by the hashing algorithm is unique. Even the slightest change in the original message or input would result in a different string of numbers, revealing that the information has been tampered with.

Hashing protocols like SHA-1 (Secure Hash Algorithm 1) and SHA-2 (Secure Hash Algorithm 2) are used for password storage, file verification, and checking data integrity during transmission. By comparing the hash value provided by the sender with the hash of the received data, recipients can make sure no one has tampered with the data during transit.

Encryption is also used in public key infrastructure (PKI) technology, which refers to secure online communications and safeguarding digital asset sharing on the public internet or company networks.

Advantages and disadvantages of cryptography

Cryptography is an essential component of secure communication. However, just like any advanced technology, it has some disadvantages that you may want to consider.

Cryptography advantages

Cryptography has numerous advantages, from protecting data integrity to facilitating secure communication. Here are some of the key pros of cryptography.

• Data security. Cryptography techniques help keep data safe and secure, ensuring it hasn’t been tampered with by someone with malicious intent.

• Confidentiality. Cryptography keeps sensitive data confidential and reduces the chances of it being compromised.

• Secure communication. Cryptography allows users to communicate more securely over the internet, protecting sensitive information during transmission.

• Protection against cyberattacks. Cryptography may prevent certain attacks (e.g., ransomware and man-in-the-middle)

• Legal compliance. Cryptography helps companies meet data protection and security requirements (e.g., GDPR and HIPAA).

Cryptography disadvantages

As with most technologies, cryptography has some disadvantages, too. One of the main issues is that it can cause many problems if misused. Here are the main drawbacks of cryptography.

• Complex to implement. Cryptography systems aren’t easy to implement and manage, which may make them less accessible to some organizations.

• Can be used for cybercrime. Cyberattackers may use cryptographic techniques for malicious purposes, from hiding criminal communications to carrying out ransomware attacks.

• Performance issues. Strong, complex encryption may sometimes slow down data transfer speeds, causing internet connection issues.

• Difficult to access information. While cryptography protects information by making it unreadable to potential attackers, it also means that sometimes, even legitimate users may not be able to access it in time.