Patent ID: 7404078

Claim:
A method of generating a certificate for use in cryptographic applications, the method comprising the steps of: receiving a first certificate on a first public key, the first public key having a corresponding first secret key; receiving additional cryptographic information other than the first public key, the additional cryptographic information being generated at least in part using at least a portion of at least one of the first secret key and a second secret key: and generating based on the additional cryptographic information a second certificate on a second public key, the second public key having the second secret key as its corresponding secret key; wherein the second certificate comprises certified cryptographic information that makes it computationally feasible for one in possession of a given one of the first and second secret keys to derive from that secret key the other of the first and second secret keys, such that a first user rightfully in possession of the first and second secret keys and the respective first and second certificates cannot lend the given secret key and its corresponding certificate to a second user without also making the other secret key accessible to the second user; and wherein it is computationally infeasible for an attacker knowing the certified cryptographic information to correlate the first and second public keys.