c. the use by a Certification Service Provider of any system other than a secure system. 4) Every Certification Service Provider shall provide every subscriber with a secure and trustworthy system to generate his key pair. 5) Every Certification Service Provider shall provide the mechanism to generate and verify advanced electronic signatures in a secure and trustworthy manner and the mechanism provided shall also indicate the validity of the signature. 6) If the advanced electronic signature is not valid, the mechanism provided should indicate if the invalidity is due to the integrity of the document or the signature and the mechanism provided shall also indicate the status of the certificate. 7) For mechanisms provided by third parties other than the licensed Certification Service Provider, the resulting signature is considered secure only if the licensed Certification Service Provider endorses the implementation of such mechanisms in conjunction with its certificate. 8) Every licensed Certification Service Provider shall be responsible for the storage of keys (including the subscriber's key and the licensed Certification Service Provider's own key) in a secure and trustworthy manner. 12