This book constitutes the refereed proceedings of the 12th International Conference on Trust, Privacy and Security in Digital Business, TrustBus 2015, held in Valencia, Spain, in September 2015 in conjunction with DEXA 2015. trust and privacy issues in mobile environments; and privacy requirements and privacy audit.

Attributes Enhanced Role-Based Access Control.- Ontology-Based Delegation of Access Control: An Enhancement to the XACML Delegation Profile.- VISIO: a Visual Approach for Singularity Detection in Recommendation Systems.- Hidden in Plain Sight: SDP-based Covert Channel for Botnet Communication.- The Design of a Configurable Reputation Service.- Attacking GSM Networks as a Script Kiddie Using Commodity Hardware and Software.- On the Efficacy of Static Features to Detect Malicious Applications in Android.- Protecting Android Apps against Reverse Engineering by the Use of the Native Code.- Designing Privacy-Aware Systems in the Cloud.- Accountability-Preserving Anonymous Delivery of Cloud Services.- Till All Are One: Towards a Unified Cloud IDS.- Security, Privacy and Usability - A Survey of Users' Perceptions and Attitudes.- Identifying Factors that Influence Employees' Security Behavior for Enhancing ISP Compliance.- Dynamic Deployment and Monitoring of Security Policies.- A Taxonomy of Requirements for the Privacy Goal Transparency.- A Privacy Preserving Framework for Big Data in e-Government Environments.- Privacy Principles: Towards a Common Privacy Audit Methodology.