Methods and systems for authenticating a security device for establishing trusted email communication. The security device is authenticated by installing private security software on the security device. In order to authorize an email transaction, a transaction authorization is performed using the security device by display a QR (Quick Response) code from an authorization server on a user terminal and scanning the QR code into the security device. After scanning the QR code, an OTA (One-Time-Authorization) code is sent from the security device to the authorization server for verifying the transaction. Embodiments of the present invention provide trusted email communication. A corresponding system for authenticating a security device and preforming trusted email communication is also provided.