A data processing system, method and program are disclosed, for managing a public key cryptographic system. The method includes the steps of generating a first public key and a first private key as a first pair in the data processing system, for use with a first public key algorithm and further generating a second public key and a second private key as a second pair in the data processing system, for use with a second public key algorithm. The method then continues by assigning a private control vector for the first private key and the second private key in the data processing system, for defining permitted uses for the first and second private keys. Then the method continues by forming a private key record which includes the first private key and the second private key in the data processing system, and encrypting the private key record under a first master key expression which is a function of the private control vector. The method then forms a private key token which includes the private control vector and the private key record, and stores the private key token in the data processing system.At a later time, the method receives a first key use request in the data processing system, requiring the first public key algorithm. In response to this, the method continues by accessing the private key token in the data processing system and checking the private control vector to determine if the private key record contains a key having permitted uses which will satisfy the first request. The method then decrypts the private key record under the first master key expression in the data processing system and extracts the first private key from the private key record. The method selects the first public key algorithm in the data processing system for the first key use request and executes the first public key algorithm in the data processing system using the first private key to perform a cryptographic operation to satisfy the first key use request.