Traditional certificates contain identification data, a public key and a digital signature which binds the public key to the user’s identification data. This signature also verifies that this binding is accepted by an authority (or trusted third-party). The public key and digital signature are distinct data elements of these traditional certificates.
An implicit certificate also contains identification data, but the public key and digital signature can be considered to be combined into a single element – the public key reconstruction data. The public key reconstruction data allows the recipient of an implicit certificate to derive the public key of the other party. This substantially reduces the amount of data that needs to be sent to the recipient, since the digital signature no longer needs to be sent. The introduction of implicit certificates has resulted in referring to traditional certificates as explicit certificates.
Last modified: 2013-12-21