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 is the process of converting readable data (plaintext) into a coded format (ciphertext), rendering it inaccessible to unauthorized users. It uses mathematical algorithms from a type of science called cryptography to scramble the data. Only those with the correct key can decrypt the ciphertext back into plaintext.

This transformation ensures that even if data is intercepted, it remains unintelligible to everyone. Imagine encryption as a locked safe; only those with the correct combination can open the safe and access its contents.

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 verifies if data has been changed, confirms the identity of users online, and guarantees messages are transferred as intended. 

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 works by converting readable information into an unreadable format. This process uses three main components: data, an encryption engine, and a key manager. In most systems, these components exist separately to reduce the risk of compromise. However, all components might run together on a single device, like a laptop.

Data exists in two states: unencrypted, meaning plaintext, or encrypted, meaning ciphertext. To transform plaintext into ciphertext, the encryption engine applies a mathematical formula known as an encryption algorithm. This algorithm follows specific rules to encode the data. 

The engine also uses an encryption key. This randomly generated string of bits creates a unique output. Only the correct key can decode data once it encrypts. Symmetric algorithms use the same key for encryption and decryption, while asymmetric algorithms use a pair of keys: one for encryption and another for decryption.

If encrypted data is intercepted, the intruder must guess both the algorithm and the key to decode it. This process is extremely time-consuming when strong encrypting methods are used. 

The complexity of the algorithm and the length of the key make it increasingly difficult to break the encryption. It’s for this reason that encryption is a trusted tool for securing sensitive information.

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

Cryptographic hash functions are a special type of encryption used to transform data into a fixed-length value called a hash. This hash represents the original data, but reversing it won't reveal it.

Even a slight change in the original data will create an entirely different hash. Hash functions are known as one-way cryptography. They lack a key in the output to reverse the process. You cannot uncover the original data from the hash.

For a hash function to be effective, it must meet specific criteria. It must be efficient enough to quickly calculate the hash for any input, but the same input should always produce the same hash. It should be preimage-resistant, meaning that the hash should hnot reveal details about the original data; it should also be collision-resistant, as different inputs should never produce the same hash.

Popular hashing algorithms include Secure Hash Algorithms (SHA) and Message Digest Algorithm 5 (MD5). Both work to secure passwords, verify file integrity, and ensure data authenticity.

Hash functions are essential for cybersecurity. Their ability to detect even minor changes to data makes them a reliable tool for maintaining trust in a digital ecosystem. 

What is an encryption algorithm?

An encryption algorithm is a set of rules that computers follow to change readable data into scrambled data. The scrambled data appears as random code, but it allows decryption using a specific key. Here are the most common examples of algorithms.

Data Encryption Standard (DES)

DES emerged in 1977 as one of the earliest symmetric encryption methods. It uses a 56-bit key to scramble data. While it was once effective, modern technology can crack DES within minutes. As a result, many consider DES outdated and insecure.

Triple DES (3DES)

3DES improves DES by encrypting data three times. It provides better security than DES but is still weaker than modern methods. Due to its inefficiency and lower security, organizations are phasing it out in favor of stronger algorithms.

Advanced Encryption Standard (AES)

People widely use AES for its balance of speed and security. This symmetric algorithm applies multiple rounds of cryptography, making it nearly impossible to crack. A 128-bit AES key could take trillions of years to break, making AES the current standard for encrypted data.

Rivest-Shamir-Adleman (RSA)

RSA is an asymmetric algorithm. It uses two keys—one public and one private. Encrypting with a public key ensures that only the intended recipient can decrypt the data with their private key. Many use RSA for secure online communications.

Twofish

Twofish is a fast and efficient symmetric algorithm. Its 128-bit keys provide strong protection against brute force attacks, making it a favorite for both hardware and software encryption. It’s also free to use.

Elliptic Curve Cryptography (ECC)

ECC is an advanced asymmetric algorithm based on complex mathematics. Its security comes from problems that take a lot of work to solve. Often considered the future of cryptography, ECC offers stronger protection than older methods like RSA.

Each algorithm type remains a powerful tool for protecting data.

Why is encryption important?

Encryption is essential for modern businesses because it secures communication and data storage while offering multiple benefits:

• Compliance with regulations and laws. Some industries, like healthcare, require encrypted data to meet privacy laws. For example, companies must encrypt patient data to avoid legal penalties for noncompliance.
• Data protection. Even if hackers bypass network security, encrypted data remains unreadable. Strong encrypted data prevents unauthorized access, as decoding would take generations using brute force methods.
• Secures data in transit. Transfers between systems creates the greatest data vulnerability. Encryption ensures that sensitive files stay protected during transfer, reducing risks of theft or loss.
• Backups verification. It helps confirm that backups remain intact and unaltered. Digital signatures ensure data authenticity, alerting recipients to any unauthorized changes. 
• Builds customer trust. Many businesses encrypt data to show they value customer privacy, even when not required by law. Transparency about practices helps companies strengthen their reputation and inspire customer confidence.

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.