SSL certificate
The padlock that encrypts a connection — proof of privacy, not of the site owner's honesty.
An SSL certificate (more precisely, TLS) is what puts the padlock and the 'https' in your browser's address bar. It encrypts the connection between your device and the website so that data in transit cannot easily be read or tampered with — and that is all it does. Crucially, it says nothing about whether the people running the site are honest.
Basic certificates are free and issued automatically with no vetting of the owner, so criminals fit them to scam sites as a matter of routine. That is why the padlock is reassurance about privacy, not proof of trustworthiness: its absence on a page asking for payment is a genuine warning sign, yet its presence tells you almost nothing about who actually runs the site. Judge a site on its address, its age, its independent reputation and how it wants to be paid, and treat encryption as table stakes rather than a seal of approval. Our article on why the padlock does not mean safe unpacks the myth, and the recognising a scam website guide puts the check in context.