A museum is an environment where users with different needs interact with each other and museum content. The need of trustworthy digital services facilitating museum management and guidance is a necessity. Nowadays mobile devices are powerful and popular. A digital museum environment should adapt mobile services to be successful. But mobile devices suffer from security vulnerabilities. The proposed system supports trustworthy mobile services based on an extended role-based access control scheme for authorization purposes. This work investigates similar systems and modern smartphone technical capabilities, along with information collected by museum experts through interviews attempting to specify user requirements. An implementation of the proposed system is provided on the context of specific real-life scenarios addressing specific services needed by museum personnel and visitors. An evaluation follows comparing the presented system with other known museum systems having as criteria the services a system should provide to support real life tasks.