Highly accurate positioning is a crucial element for the development of various categories of mass-market and professional position-based applications such as some Location Based Services (LBS), Road Applications, High Precision Agriculture and Disaster Alerting. By 2022, according to the GNSS European Authority (GSA) Market Report (October 2013) [GSA, "GNSS Market Report issue 3, 2013," October 2013], LBS will represent the largest market in GNSS (47%) followed by Road segment (46.2%). Moreover, thanks to a continuing reduction in costs and increase in performances of satellite navigation receivers, the dependence of these applications on satellite navigation systems is expected to grow further, especially in the mass-market segment, which is driven by the explosion of mobile and embedded devices like smartphones and tablets. In this scenario, the EGNOS/EDAS system represents a key technology to improve the positioning performances of GNSS mass-market receivers. The EGNOS/EDAS system can increase the accuracy of position measurements by transmitting information that correct satellite navigation data and by providing an evidence of positioning reliability through the integrity messages. For all these reasons, engineers and researchers in the field of GNSS are exploring alternative methodologies to exploit the benefits deriving from the use of EGNOS/EDAS. New opportunities are arising, among others, from the integration of the GNSS technologies with emerging ICT technologies, e.g. cloud computing. In this paper, the authors want to propose and analyse a cloud-based architecture for centralized computation of augmentation and integrity based on EGNOS/EDAS information services. This solution aims to demonstrate that this innovative approach could represent a valid alternative to the standard access to EGNOS through Signal-In-Space (SIS), providing a centralized platform which is able to serve a large number of devices, via standard terrestrial communication channels, with high-accuracy positioning based on reliable EGNOS/EDAS services in a Navigation-as-a-Service (NaaS) approach.