Security glossary

The most important terms around VPN, privacy and online scams – explained briefly and clearly.

Browser fingerprint

Features such as screen, time zone and fonts form an identifier that lets websites recognise you without cookies.

Browser check

Data leak

When a service's customer data such as e-mail addresses or passwords becomes public without authorisation.

Leak check

DNS

The phone book of the internet: it translates names like example.com into IP addresses. Whoever sees your DNS requests knows which sites you visit.

DNS leak

When DNS requests bypass the tunnel and go to your internet provider despite the VPN. Then it is visible which sites you visit, even though the rest of the traffic is encrypted.

Encryption

Data is transformed so that only the right recipient can read it. To everyone else it looks like gibberish.

Evil twin (fake hotspot)

A Wi-Fi network posing as a familiar one, such as “Airport Free WiFi”. Anyone who connects sends their data through the attacker's device.

Guide: public Wi-Fi

IP address

The number under which your connection can be reached on the internet. It reveals your provider and approximate location.

IP check

Kill Switch

A safety feature: if the VPN connection drops, internet traffic is stopped so that nothing slips through unprotected.

Guide: kill switch

Malware

Umbrella term for malicious software such as viruses, trojans or spy apps.

No-log policy

A VPN provider's promise not to record which sites you visit. Pay attention to what exactly is excluded.

OpenVPN

A proven, open-source VPN protocol. Performance VPN uses OpenVPN – you connect, for example, with the OpenVPN Connect app.

Guide: set up OpenVPN

Passkey

Signing in without a password, by fingerprint, face or device PIN. It only works on the real website and so protects against phishing.

Phishing

Fake e-mails or websites designed to steal passwords, one-time codes or card details.

Link check

Proxy

An intermediary that forwards requests on your behalf. Unlike a VPN, it usually does not encrypt all traffic.

Quishing

Phishing via QR codes, for example fake stickers on parking meters or codes in letters.

QR code check

Ransomware

Malware that encrypts your files and demands a ransom. The best precaution is a current backup.

First aid

Smishing

Phishing by text message, for example supposed parcel or bank messages with a link.

Phishing quiz

Split Tunneling

Only part of the traffic goes through the VPN, the rest directly – for example so the printer on your home network stays reachable.

Spoofing

Faking a sender – in e-mails, calls or texts. The displayed name says nothing about who is really writing.

Mail check

Two-factor sign-in (2FA)

Signing in requires a second proof besides the password, such as a code from an app. A stolen password alone is then not enough.

Two-factor guide

VPN

A virtual private network sends your internet traffic encrypted through a server. Websites then see its IP address instead of yours, and nobody on the same Wi-Fi can read along.

Guide: What is a VPN?

WebRTC leak

Browsers use WebRTC for video calls. In the process the real IP address can reach websites – sometimes even past a VPN connection.

IP check