If you see connections to ocsp.digicert.com in your browser or in your network traffic logger, there’s no need to worry. ocsp.digicert.com is DigiCert’s OCSP (Online Certificate Status Protocol) server and is used to check the revocation status of DigiCert’s digital certificates.
Here’s a screenshot of the ocsp.digicert.com HTTP requests and responses:
If you see Google Chrome, Mozilla Firefox or Internet Explorer connecting to ocsp.digicert.com, they are in the middle of the process of verifying a digital certificate. Perhaps a certificate for a HTTPS connection you just made?
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