CITS3002 Computer Networks  
← prev
next → CITS3002 help3002 CITS3002 schedule  

Browser support for digital certificates

 The browser will display the digital certificate from the current page - here showing:

  • The subject of the certificate,
  • The issuer (CA) of the certificate,
  • The serial number of the certificate,
  • The period of validity of the certificate, and
  • The message digest of certificate.

If the issuer of a site's digital certificate is already known by the browser (either 'hard-wired' or manually added), the issuer's certificate may be viewed and verified.

Version 3 of X.509 introduced extension fields - the association of additional information with a certificate. Each extension has:

  • an extension type providing semantics and typing of the extension (e.g. a string),
  • an extension value", such as an email or IP address, and
  • a criticality indicator indicating if the whole certificate should be ignored if an extension is not recognized.

Standard extensions (?) now describe the 'strength' and purpose of the certificate - digital signature, non-repudiation, key encipherment, data encipherment, certificate signing, etc.


CITS3002 Computer Networks, Lecture 12, Cryptography's role in networking, p23, 22nd May 2024.