About the Expiration of Personal Certificates

MIT secure web certificates do not last forever. They are the key to many services at MIT, and for security reasons, are given a limited lifetime:

  • Personal certificates are renewed every year on or before July 30.
  • MIT CA (Certification Authority) certificates are valid until August 2026.

You may get a new personal certificate at any time, whether or not existing ones have expired. To determine if they have expired, see: Q: How do I check certificate expiration dates?

Note: In Firefox on all platforms, and Internet Explorer on Windows, unexpired and expired personal certificates can coexist. In Safari on Mac OS X, an expired MIT personal certificate may interfere with getting to MIT certificate-protected websites, even if you have an unexpired certificate; therefore, IS&T recommends deleting expired certificates.

Warning: On any platform, if you send or receive email which has been signed or encrypted with your personal certificate (S/MIME), you must keep that certificate on your system even after it expires, in order to validate and read the email.

Export your expired certificates from your browser to a backup file and delete them from your browser before you get new certificates.

Find out if you're using S/MIME.