Part 1 of this series specifies the application interface to Smart Cards during the usage phase, used as Secure Signature Creation Devices (SSCD) according to the Terms of the European Directive on Electronic Signature 1999/93 to enable interoperability and usage as SSCD on a national or European level. This document describes the mandatory services for the usage of Smart Cards as SSCDs based on CEN CWA 14890 (all parts). This covers the signing function, storage of certificates, the related user verification, establishment and use of trusted path and channel, requirements for key generation and the allocation and format of resources required for the execution of those functions and related cryptographic token information.