Patent ID: 8688976

Claim:
A method for issuing a digital certificate by a certification authority, comprising: a device sending a request for the issuing of the digital certificate to the certification authority, the certification authority receiving the request message, generating a random number y known only to the certification authority and sending a first value Y=g y as a challenge to the device, where g is a generator in accordance with the Diffie-Hellman method, the device receiving the challenge, calculating a second value Y x from the received challenge Y, and sending said second value Y x to the certification authority as a response to the challenge, where x is a third value known only to the device, and the certification authority calculating a fourth value X y , where X=g x is a fifth value known both to the device and to the certification authority, comparing the calculated fourth value X y with the second value Y x received from the device, and sending the digital certificate to the device if the second and fourth values match.