What encryption is, and where you are already using it

The idea

Encryption turns readable information into scrambled data using a mathematical key. Only someone with the right key can turn it back. Without the key, the data is useless, even to someone who has a copy.

In transit

When data travels across a network, encryption stops anyone in between from reading it. This is what the https:// and padlock in your browser mean, and it also protects email between servers, Teams calls and remote access connections.

At rest

When data is stored, encryption protects it if the device is lost or stolen. A laptop with its drive encrypted, using BitLocker on Windows or FileVault on a Mac, shows nothing to a thief who removes the drive. Phones with a screen lock are encrypted too.

End-to-end

Some messaging apps encrypt messages so that only the sender and recipient can read them, and the company running the service cannot.

What it does not do

Encryption protects data from people who do not have the key. Anyone signed in as you has the key. If someone steals your password, or malware runs while you are signed in, encryption does not stop them. That is why it works alongside multi-factor authentication and protection on the device.