Certificate and Key Formats

Certificates are often known as X.509 certificates, since X.509 is the standard that defines their context and layout. The commonest algorithms for creating public and private keys are RSA and DSA, and keys are often referred to as RSA keys or DSA keys. None of these, however, define the format of the file in which a certificate or key is held. There are many rival formats for these files. Some of the commonest standard formats are: