To get a digital certificate from the public key infrastructure, the standard format followed is the X.509. It has been accepted as the defacto standard and has been recommended by the International Telecommunication Union (ITU).

It has been published as an extension of X.500 which is similar to the telephone book. In the X.509 version some of the standard formats are published for public key certificates, certificate revocation list, attributes certificate and a certification path validation algorithm. Using the X.509 standard certificate authority will issue a certificate binding a public key or an alternative name like E-mail address to the certificate. Below are the formats of the various versions of X.509.

This Paper is written & submitted by Deepak V.