| 摘要 |
<p>The present invention relates to a method and to an apparatus for access control and identification which requires no public key directory. For many applications, e.g. smart cards for pay TV purposes, credit cards, passports, dongles or other kind of electronic keys, unforgeable systems for access control or digital signature are required. Such access control and systems may include public keys. But in many of such public key systems the key management becomes very complicated when the number of users increases. The invention uses the fact that it is difficult to compute square roots mod n when factoring of n is unknown. The invention is based on the identity: x?2 r(x+x-1) 2 = r2 1+x2 2¿ mod n which is computed and compared using a user unit and a verifier unit. The public key directory is replaced by a unique transmission between a sender and a receiver R of a 'seed' which will give after a proper processing both the identity information for R and public keys.</p> |
