Encryption is a powerful way to keep digital information private and secure. From messaging apps to banking websites, it protects our data every day - often without us even noticing.
Whether you're a consumer curious about how private messages stay private, or a business leader looking to safeguard customer data, this guide breaks down what encryption is, how it works, and why it matters in the real world.
Encryption is the process of turning readable information - called plaintext - into unreadable text, known as ciphertext, using a mathematical formula and a secret key.
Only someone with the right decryption key can convert the ciphertext back into something understandable.
Without the key, the scrambled message looks like random characters - unreadable to hackers, eavesdroppers, or anyone else.
In simple terms, encryption works like a digital lock.
It protects your data while it's stored on a device or flying across the internet, making sure only the right person can unlock and read it.
Example: If Emma wants to send David a secret message - "HELLO" - she could shift each letter by 2 characters, turning it into "JGNNQ". Unless David knows the rule (the key), the message remains meaningless.
Modern encryption uses highly advanced maths and massive keys - sometimes 256 bits long - but the principle is the same: without the key, the content stays secure.
Encryption works using algorithms (sets of mathematical rules) and keys (secret codes that lock and unlock the information).
When you encrypt data, you're using an algorithm to scramble it with a key. The same algorithm, along with the matching key, is then used to decrypt it.
There are two main approaches used in practice - and often, they’re combined for stronger results.
Symmetric encryption uses the same key to both encrypt and decrypt data.
It’s fast and ideal for protecting large amounts of information, like entire files or databases.
But there’s a catch - everyone who needs access must share the same secret key, and that key must be delivered securely.
If someone steals the key, they can read everything.
Common symmetric algorithms include:
Asymmetric encryption, or public-key encryption, uses two keys - a public key (shared openly) and a private key (kept secret).
You can give your public key to anyone.
They can use it to encrypt a message to you. But only you - with your private key - can decrypt it.
This makes it ideal for secure communication between strangers online. It’s slower than symmetric encryption, so it’s usually used to secure the exchange of symmetric keys - then symmetric encryption takes over for the actual data.
Common asymmetric algorithms include:
Most modern systems use a combination of both types.
Example: When you visit a secure website, your browser and the server use asymmetric encryption to exchange a symmetric key - then that key is used for the rest of your session.
This approach is the backbone of technologies like TLS 1.3, VPNs, and email encryption protocols - giving you both speed and security.
You may not see it, but encryption works behind the scenes every time you message a friend, shop online, or back up files to the cloud.
Here are some of the most common ways encryption protects everyday digital activity:
Apps like WhatsApp, Signal, and iMessage use end-to-end encryption (E2EE).
This means your messages are encrypted on your device and only decrypted on the recipient's device.
No one else - not even the app provider - can read them.
When a website starts with "https://", the 's' stands for secure - it means the site is using TLS 1.3 to encrypt all data you send or receive.
This protects credit card numbers, passwords, and other personal data from hackers while you shop, log in, or bank online.
When you upload files to services like Google Drive, Dropbox, or iCloud, those files are typically encrypted both in transit and at rest.
That means they’re scrambled as they travel across the internet and while they’re stored on the service’s servers - so your photos, documents, and backups stay private.
Home Wi-Fi networks use WPA2 or WPA3 encryption to protect the data travelling between your devices and your router.
If you use a VPN (Virtual Private Network), your entire internet traffic is encrypted - especially useful when using public Wi-Fi at cafés, airports, or hotels.
Most modern devices include full-disk encryption features - like Apple’s FileVault, Android device encryption, or Windows BitLocker.
If your phone or laptop is lost or stolen, encryption ensures that no one can access your files, even if they remove the hard drive or bypass the login screen.
Encryption isn’t just for tech experts. It plays a vital role in everyday privacy, business security, and digital trust.
According to the UK survey, cyber attacks continue to threaten organisations of all sizes, and encryption is a critical layer of defence.
The market report on encryption software shows rapid growth as more businesses invest in secure communications tools.
UK firms have doubled their encryption policy use since 2022, reflecting greater urgency around digital security.
Encryption is also a societal issue.
According to encryption society research, it plays a foundational role in freedom of speech, press, and individual rights.
Neglecting encryption comes with consequences.
In a business breach study, organisations suffered reputational, legal, and financial fallout following cyber attacks that could have been mitigated with strong encryption.
From GDPR in Europe to HIPAA in the US, data laws across the globe recommend or require encryption for sensitive information.
By using encryption, organisations not only stay compliant - they also reduce the risks of fines, legal action, and reputational damage in the event of a breach.
"Encryption protects the data we rely on every day - and it earns the trust we build our businesses on."
Carole Howard, Head of Networks, Beyond Encryption
Encryption works best when paired with good habits and the right tools. Here are key best practices for using encryption safely and effectively:
Choose encryption tools that use trusted standards like AES-256 for data encryption and TLS 1.3 for network protection.
Avoid outdated or broken algorithms such as DES or SSL, which no longer offer effective protection.
When privacy is essential - in messaging, video calls, or document sharing - look for solutions that offer end-to-end encryption (E2EE).
Only sender and recipient should be able to read the content. If a provider doesn’t use E2EE, your data could be accessed in transit or on their servers.
Encryption is only as secure as the keys used to protect it.
Store keys separately from the data they protect. Use hardware security modules (HSMs) or trusted key vaults. Rotate keys regularly and limit who has access.
Make sure encryption is applied when data is stored (on devices, servers, or cloud systems) and when it’s being sent across networks (emails, websites, file transfers).
Encrypting in both states helps close any security gaps.
Use the latest versions of your security tools, operating systems, and apps. Updates often patch flaws that attackers exploit.
This includes your browsers, email clients, VPN software, and cloud tools.
Encrypting data is one thing - but if your password or device is easy to break into, the encryption won’t matter.
Use long, unique passwords and enable multi-factor authentication (MFA) wherever possible.
For businesses, encryption is only effective if employees understand how to use it correctly.
Run regular awareness sessions, and build encryption into company policy for data protection, file sharing, and device usage.
"Technology is essential, but training is just as critical. People are often the weakest link in the security chain - encryption or not. That's why authenticating identity is becoming more relevant."
Paul Holland, Head of Network Sales, Beyond Encryption
Encryption is a method of turning readable information into a scrambled format so that only someone with the right key can read it.
It protects privacy, secures sensitive information, helps prevent data breaches, and ensures legal compliance for businesses.
Data at rest is stored on a device or server, while data in transit is moving across a network. Both need encryption to stay secure at all times.
End-to-end encryption ensures that only the sender and recipient can read a message. Even the service provider cannot access the contents.
Modern encryption is very secure. But poor password habits, misconfigured software, or stolen keys can expose encrypted data. That’s why best practices matter.
Study of Cryptography, IJRAR, 2023
UK Firms Double Encryption Policy Use in 2024, Data Centre News UK, 2024
Cyber Security Breaches Survey, UK Government, 2024
Encryption Software Market Report, Yahoo Finance, 2024
Encryption & Society, CEPA, 2023
Data Encryption & Protecting Sensitive Information, Endpoint Protector, 2023
Encryption Pros and Cons, UCL, 2023
The Devastating Business Impacts of a Cyber Breach, Harvard Business Review, 2023
Sam Kendall, 20.06.25