What Is Encryption? A Plain-English Guide for Business Owners

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Encryption, without the maths lesson

Encryption sounds like something for spies and software engineers. In reality, you use it dozens of times a day, and it’s one of the simplest, most effective ways to protect your business. You don’t need to understand the maths behind it. You just need to know what it does and where to switch it on.

This guide explains encryption in plain English: what it is, the two main types, where you already rely on it, and the handful of practical steps that keep your data safe.

What encryption actually does

Encryption scrambles readable information into a coded form that looks like meaningless nonsense. Only someone with the right key can turn it back into something readable.

Think of it like a locked safe. Anyone can carry the safe away, but without the combination the contents are useless to them. Encryption does the same for your data: even if a criminal steals it, they can’t read it without the key.

That single idea, unreadable without the key, is why encryption matters so much. It turns stolen data into worthless gibberish.

Encryption turns a stolen laptop or an intercepted email from a serious breach into a shrug, because the data inside is useless without the key.

The two types you’ll meet

Almost all encryption falls into one of two jobs.

Encryption at rest

This protects data while it’s stored somewhere, on a laptop, phone, USB stick, server or in the cloud. If the device is lost or stolen, the contents stay locked.

The classic example is disk encryption. If a member of staff leaves an encrypted laptop on a train, whoever finds it sees only scrambled data, not your client records. Without encryption, that same laptop could be a reportable data breach.

Encryption in transit

This protects data while it’s moving, typically across the internet, between your browser and a website, or between your email app and the mail server. It stops anyone who intercepts the connection from reading what’s inside.

You want both. At rest protects data sitting still; in transit protects it on the move. Together they cover the whole journey.

Where you already use encryption

The good news is that a lot of encryption is already built in and free. You’re probably using it without noticing.

HTTPS and the padlock

Every time you see ‘https://’ and a padlock in your browser, the connection to that website is encrypted. Anything you type, passwords, card numbers, form details, is protected in transit. If a site only shows ‘http://’ with no padlock, treat it with caution and never enter sensitive information.

Device and disk encryption

Most modern devices can encrypt their entire storage, usually with a setting you just switch on:

• Windows offers BitLocker on business editions, and Device Encryption on many others.
• Macs use FileVault.
• Phones and tablets (iPhone and modern Android) are encrypted by default once you set a passcode.

Turning this on is one of the highest-value, lowest-effort security steps you can take. It’s also expected under Cyber Essentials for mobile devices. Pair it with a decent passcode or password, because encryption only helps if the device is actually locked.

Encrypted email and storage

Standard business email (Microsoft 365, Google Workspace) is encrypted in transit between the big providers, which covers most everyday risk. For genuinely sensitive material you can go further with services built around encryption from the ground up.

Providers like Proton Mail offer end-to-end encrypted email and encrypted cloud storage through Proton Drive, meaning even the provider can’t read your content. For a small business handling confidential client information, that extra layer can be worth having alongside your main email. A password manager uses the same principle to keep your logins encrypted.

Why it matters for your business

Encryption isn’t just a technical nicety. For a UK small business it delivers three concrete benefits.

1. It protects your customers and reputation. A lost device or intercepted email doesn’t have to become a headline or a difficult conversation with clients.
2. It supports your legal duties. UK data protection law expects you to keep personal data secure, and the ICO points to encryption as a recognised way to do it. Encrypting devices and sensitive data helps you meet that expectation, as covered in our GDPR basics guide.
3. It reduces the fallout from theft. An encrypted, lost laptop is often not a reportable breach at all, because the data on it can’t be accessed. Unencrypted, the same loss could mean notifying the ICO and your customers.

Getting started: a short checklist

You don’t need a big project to benefit. Start here:

• Turn on disk encryption on every laptop and PC (BitLocker or FileVault) and set a strong passcode.
• Check your phones and tablets have a passcode set, which enables their built-in encryption.
• Look for the padlock before entering anything sensitive on a website.
• Use encrypted storage and backups so copies of your data are protected too, part of a solid backup strategy.
• Consider encrypted email for your most confidential communications.

The bottom line

Encryption is one of the rare security measures that is powerful, widely built in, and mostly free. You don’t need to understand how it works to benefit, you just need to switch it on and use services that take it seriously. Encrypt your devices, look for the padlock, and protect your most sensitive data with encrypted email and storage.

If you’d like a hand making sure your laptops, phones and cloud services are properly encrypted, get in touch with DACROS. We help small businesses across Leeds and Yorkshire lock down their data without the jargon, and you can see how we work on our cyber-security page.