Encryption

Encryption is a way of scrambling information so only the person holding the right key can read it. Picture a locked box. Anyone can carry that box, copy it or steal it, and the writing inside stays useless to them. Opening it needs the key. The key is a long secret number your device keeps, and the maths behind it is not something you ever have to understand.

Two different moments need it, and people mix them up. The first is information on the move. An order leaving a customer's phone, an email going out, a photo uploaded to your site. The second is information sitting still. Files on a laptop, a backup on a hard disk, customer names resting in a database. Protecting one does not protect the other, and most businesses only ever do the first.

The travelling half is usually handled for you. That padlock in the address bar means the line between the visitor and the server is scrambled, so nobody on the café wi-fi can read it. The sitting-still half is the one that gets forgotten. A shop can have a perfect padlock on its website and still keep a plain copy of every customer address on an old laptop in the back room. When that laptop walks out of the door, the padlock counted for nothing. Linkysoft asks where the copies live before it asks anything else about security work.

Now the uncomfortable part. Encryption does not save you from a stolen password. If a thief signs in with your name and your password, the system opens everything for him, politely, because it believes he is you. The lock worked exactly as it was built to work. This is why a second step at sign-in, a code on your phone, is worth more than any improvement to the maths. It is also why four staff should never share one login.

Ask a supplier two plain questions. Where are the keys kept, and who on your team can read customer data without asking anyone. A good answer names very few people. When Linkysoft builds a web application, card numbers and identity documents are stored scrambled and apart from the rest, so one mistake never exposes everything at once. That costs a little more at the start and far less the day something goes wrong.