Digital certificate

A digital certificate is an electronic ID that proves a website or app is run by who it claims and lets your device set up an encrypted link.

Digital certificate: A digital certificate is an electronic document that links a website or software to its owner. A trusted authority issues it. Your browser checks it when you open an HTTPS site, to confirm the name matches and to start an encrypted connection.

When your browser shows a certificate warning, it says the identity check failed. Causes include a wrong date on your phone, a poorly set up site, or a real attack where someone sits between you and the site. People often tap proceed anyway because they want to finish quickly, which defeats the check. A certificate check happens in a second, so any warning that appears is worth reading.

Certificates also exist for software and are the basis of app signing. A certificate is proof of a name, not proof of good intent, because criminals can buy one for their lookalike domain. Treat a certificate warning on a bank or payment site as a stop sign, check your phone date and try another network. Fraud pages can also carry a valid certificate, so the name still needs a careful look.

Tips

• Never tap proceed anyway on a certificate warning for a bank, UPI or shopping site.
• Check that your phone's date and time are set to automatic.
• Try a different network, such as mobile data, if a site keeps showing a certificate error.

Related terms