Methods and systems are provided for performing and verifying transactions involving authentication with a secure credential, such as a smart card, in an untrusted or semi-trusted environment. An application module, operating in an untrusted or semi-trusted environment can be denied access to sensitive data. The application module can determine a preliminary command to be sent to the credential and transmit the preliminary command to a broker module. The broker module, operating in a trusted environment, can supply sensitive data and transmit the command to the credential. Subsequently, the broker module can extract sensitive data from a response before it is transmitted to the application module. A verification server can audit the transaction to verify that it was carried out properly.