Abstract: A multiple use ticket generating method is disclosed which enables a recipient to obtain signatures for arbitrarily many (correctly formed) messages after only one interaction with the signer. The method provides a blind signature in a ticket, the signature having a multiple use with a built-in expiration. Then, the method develops a blinding value for the signature in a reproducible computation using a seed key substantially known only to the issuer of the ticket. The method implements a new class of signature schemes almost as efficiently as do previous one-time restrictive blind signature methods.

Abstract: A multiple use ticket generating method is disclosed which enables a recipient to obtain signatures for arbitrarily many (correctly formed) messages after only one interaction with the signer. The method provides a blind signature in a ticket, the signature having a multiple use with a built-in expiration. Then, the method develops a blinding value for the signature in a reproducible computation using a seed key substantially known only to the issuer of the ticket. The method implements a new class of signature schemes almost as efficiently as do previous one-time restrictive blind signature methods.

Abstract: In a method and a distribution system for the secure distribution of security modules, particularly for postage meter machines, for protecting against manipulation of security modules, only devices with security modules whose keys have not been comprised can be placed in operation by the customer under all circumstances, i.e. even when the cryptographic initialization at the production location has been comprehensively undermined. The generation and checking of markings, potentially in combination with certificates proceeds with a first marking of the shipping packaging of the security module ensuing at the manufacturing location after a first cryptographic initialization. The first marking is preferably a public key printed on a first label.