What Is Encryption and How Does It Work?

We constantly send data in our day-to-day lives. But what stops someone from stealing or intercepting our data? Encryption serves as an important tool in this protection process. As it converts readable data into code, it safeguards personal or sensitive information, such as texts or passwords.
In this article, learn what encryption is, how it works, and the types that exist.

What is encryption?

Encryption turns readable data, called plaintext, into unreadable code, called ciphertext. This keeps the data safe from anyone who doesn’t have permission to see it. It uses math rules from cryptography to scramble the data. Only someone with the right key can unlock it and turn it back into readable form.

This transformation keeps the data safe even if someone manages to intercept it. Think of encryption like a locked safe. Only people with the right combination can open it and see what's inside. Without the key, the contents stay hidden.

It aims to protect sensitive data against unlawful data breaches, theft, or tampering, whether stored or transmitted. In the past, encryption safeguarded sensitive information, and governments relied on it for secure communication. 

Encryption protects data in two forms: at rest and in motion. The former refers to information stored on devices like computers or hard drives. In-motion data is the kind sent between devices or across networks. Financial transactions depend on this type of cryptography to remain confidential. It secures information whenever someone makes an ATM transaction or uses a smartphone to shop online.

Data cryptography helps check if information has been tampered with. It proves who someone is online, and ensures that messages are sent and received correctly.

Beyond maintaining privacy, encrypted data ensures data authenticity by proving that nothing changed from its original state. This technology confirms the integrity of information during online transactions or document transfers. 

The process is not just about hiding sensitive information from prying eyes. It also builds trust in online interactions via confirming that people are communicating with who they believe they are. It plays a critical role in safeguarding information, preventing fraud, and keeping the digital world secure for everyone.

How does encryption work?

Encryption turns readable information into scrambled text so that no one else can read it. It uses three main parts: the data, an encryption engine, and a key manager. These are often kept separate to stay secure. But sometimes, like on a laptop, they all run on the same device.

Data comes in two forms: plaintext, which is easy to read, and ciphertext, which is scrambled and unreadable. To turn plaintext into ciphertext, an encryption engine uses special rules called an encryption algorithm.

The engine also uses an encryption key: a string of random numbers or bits that makes each encrypted message unique. There are two main types of encryption:

• Symmetric encryption, which uses the same key to lock and unlock the data.
• Asymmetric encryption, which uses two different keys - one to lock (encrypt) and another to unlock (decrypt).

If someone tries to steal the data, they would need both the right algorithm and the correct key. With strong encryption, guessing them would take too much time to be worth it.

That’s why encryption is one of the most trusted ways to protect private or sensitive information today.

Different types of encryption

Encryption is classified into various main types: symmetric, asymmetric, and hash functions. All serve to protect data, but they work differently and have unique strengths. 

Symmetric encryption

Symmetric encryption, also known as symmetric ciphers or secret key ciphers, uses a single key to encrypt and decrypt data. This key, often a password or a random string of numbers, is typically generated by a random number generator (RNG). Symmetric encryption is the simplest and fastest form. It is ideal for applications requiring speed, such as securing large data sets.

The two primary forms of symmetric encryption algorithms are block algorithms and stream algorithms.

• Block algorithms encrypt blocks of plain text as a single group.
• Stream algorithms encrypt one symbol of plain text at a time, directly converting it into ciphertext.

Though symmetric encryption is efficient, its security hinges on the key remaining private. Sharing the key securely between parties can be a weakness.

Asymmetric encryption

Asymmetric encryption, also referred to as asymmetric ciphers or public key cryptography, uses two keys: a public key and a private key. The public key is shared openly, unlike the private key, which remains confidential. Depending on the purpose, these keys work together to encrypt and decrypt data.

• Encrypting with the public key ensures that only the corresponding private key can decrypt the message. This prevents unauthorized access, even during data transmission.
• Encrypting with the private key confirms the sender’s identity, as only the matching public key can decrypt the message accurately.

Asymmetric encryption is highly secure. However, because it requires longer keys, it tends to be slower and more resource-intensive. It can strain networks, memory, and battery life. Many use this technology for secure communications in scenarios demanding strong authentication.

Today, however, symmetric and asymmetric methods are often combined. This approach leverages the efficiency of symmetric encryption with the advanced security of asymmetric methods to compensate for each other’s weaknesses.

Hash functions

A cryptographic hash function is a tool that turns data into a fixed-length string of characters called a hash. This hash looks nothing like the original data, and it’s impossible to reverse the process to figure out what the original input was.

Even a tiny change in the original data will create a completely different hash. That’s why hash functions are considered one-way - they don’t use keys like normal encryption, and there’s no way to “decrypt” them.

For a hash function to work well, it needs to follow a few basic rules. It should be fast to use and always give the same result for the same input. It also shouldn't give away anything about the original data, and different pieces of data should never end up with the same hash.

Some well-known hash algorithms are Secure Hash Algorithm (SHA) and Message Digest Algorithm 5 (MD5). These are often used to protect passwords, check that files haven’t been changed, and make sure digital information is real and trustworthy.

Hash functions are important in cybersecurity because they can quickly detect even the smallest changes in data. This makes them a reliable way to help protect sensitive information online.

What is an encryption algorithm?

An encryption algorithm is a set of steps a computer follows to turn readable data into scrambled data. It can be unlocked with the right key. Here are the most common examples of algorithms.

Data Encryption Standard (DES)

DES came out in 1977 as an early symmetric encryption method. It uses a 56-bit key to scramble data. Today, it's easy to break, so it's considered outdated and unsafe.

Triple DES (3DES)

3DES improves on DES by running the encryption process three times. This makes it more secure than DES, but it's still slower and weaker than newer methods. Because of this, many organizations are moving away from it.

Advanced Encryption Standard (AES)

AES is popular because it’s both fast and secure. It uses several rounds of encryption to protect data, and even a 128-bit key would take trillions of years to break. That’s why AES is the standard for keeping data safe today.

Rivest-Shamir-Adleman (RSA)

RSA is an asymmetric encryption method that uses two keys: one public and one private. When data is encrypted with the public key, only the private key can unlock it. This makes RSA useful for secure online communication.

Twofish

Twofish is a symmetric algorithm that’s fast and strong. It uses 128-bit keys to defend against brute force attacks. Many choose Twofish for its efficiency and because it’s free to use.

Elliptic Curve Cryptography (ECC)

Elliptic Curve Cryptography (ECC) is a modern asymmetric method based on complex math. It offers strong security with smaller keys, making it more efficient than older systems like RSA.

These algorithms all play key roles in keeping digital information safe.

Why is encryption important?

Encryption is important for modern businesses because it keeps communication and data safe. It also brings several key benefits:

• It helps meet legal rules. In industries like healthcare, companies must encrypt data to follow privacy laws. For example, patient data must be encrypted to avoid legal trouble.
• It protects data from hackers. Even if someone breaks into a system, encrypted data looks like random code. Without the right key, it's nearly impossible to read.
• It keeps data safe during transfers. Moving data between systems is risky. Encryption protects the data while it’s being sent, lowering the chance of theft or loss.
• It checks backup safety. Encryption can help prove that backups haven’t been changed. Digital signatures show whether data is real or has been tampered with.
• It builds customer trust. Even when not required, businesses that encrypt data show they care about privacy. Being open about encryption practices can improve a company’s reputation.

Applications of encryption

Encryption secures information across various areas of modern technology. Its applications are as follows.

Secure online transactions

Encryption protects financial and personal information during online transactions. Technologies like HTTPS and Transport Layer Security (TLS) encrypt data exchanged between a user’s device and a website. This way, a hacker cannot intercept credit card information. 

Email encryption

Emails often contain private information, thus making them a target for cybercriminals. Methods like PGP (Pretty Good Privacy) and S/MIME (Secure/Multipurpose Internet Mail Extensions) secure emails by converting the content into unreadable formats. Only the intended recipient, with the proper decryption key, can read the email.

Cloud storage and file sharing

Encrypted data keeps your information private as more people store files and share information through cloud services. When files are end-to-end encrypted before being uploaded, they cannot be read or accessed by anyone without permission. 

Mobile device security

Internet-enabled devices store personal data such as photos, messages, and passwords. Cryptography lets you protect this information with a key often linked to the user’s passcode or fingerprint. This type of cryptography makes the data inaccessible without proper authorization even if you lose your device.

Frequently asked questions

Can encryption be broken or hacked?

Yes, weak methods can be broken, but strong algorithms are hard to hack without the key.

Is encryption used in cloud storage?

Cloud services use encryption to secure stored data and ensure that only authorized users can access it.

How do I encrypt my emails?

You can use tools like PGP or S/MIME to encrypt emails to protect your messages from unauthorized access.