METHOD FOR THE APPLICATION OF IMPLICIT SIGNATURE SCHEMES

A method of certifying a correspondent in a data communication system by a certifying authority. The certifying authority includes a cryptographic unit. The method includes generating a random number and implicit certificate components based on the random number using the cryptographic unit. The implicit certificate components have a first component and a second component. The method also includes providing the implicit certificate components for use in the data communication system and providing a public key of the certifying authority for use in derivation of a public key of the correspondent from the first component. The certifying authority recertifies the correspondent by providing implicit certificate components using a changed value for the random number.