246 ITU‐T's Technical Reports and Specifications Encryption of data traveling over a public network (Internet) so that nobody can decipher its contents. National coverage. Massive transfer of information. 2.2 ICT facilities: over the top, services, applications and contents This section addresses the application and security layers illustrated in Figures 4 and 5, and contains specifications for corresponding ICT facilities. 2.2.1 ICT integrated services capacity The capacity of integration of services has a direct relationship with interoperability, which is decisive. Every entity involved in the development SSC applications shall adopt open standards that enable interoperability between information systems with the systems of other actors, public and private, and for data captured through smart devices of citizens serve as basis for open and reuse data and generate new services and platforms. 2.2.2 Data management 2.2.2.1 Data security As stated in the European Commission Project SMARTIE (Secure and Smarter Cities Data Management)9: \"A secure, trusted, but easy to use (…) system for a smart city will benefit the various stakeholders of a smart city. This also holds true for SSC. The city administration will find it easier to get information from their citizens while protecting their privacy. Furthermore, the services offered will be more reliable if quality and trust of the underlying information is ensured\". There are numerous risks to be addressed involving all levels of data of the system itself, and considering citizens' concerns about data intrusion, then security becomes a key concept in the adoption and sustainability of a smart city, some of these risk are10: Event‐driven agents to enable an intelligent/self‐aware behavior of networked devices. Authentication and data integrity. Models for decentralized authentication and trust. Security and trust for cloud computing. Data ownership, repository data management, privacy policies management and privacy preserving technologies. Legal and liability issues (etc.). 2.2.2.2 Integration of heterogeneous data The sensing of urban spaces and the participation of society in the generation of content and social networks exponentially increases the volume of information available. There are three \"V\" of interest in large data volumes (i) the Volume or the amount of processed information, (ii) the Variety of the types of data that can be represented, and (iii) the Velocity (speed) at which are captured, transferred and processed these data. ____________________ 9 Security and Privacy Challenge in Data Aggregation for the IoT in Smart Cities (from http://www.smartie‐project.eu/publication_ bohli2013a.html) 10 Taken from \"Internet of Things Strategic Research Roadmap\" Page 34