Summary
Personal Cloud (PC) storage services such as Dropbox or Google Drive have become increasingly popular in the last few years. Unfortunately, these services are still not secure. Even assuming “perfect” data confidentiality, securely sharing a folder in these services is still an issue, and this without mentioning the fact that the existing sharing mechanisms are typically too coarse‐grained by operating at the folder level. This is insufficient in many real situations where it is more natural to grant or deny access to files based on arbitrary user attributes and selected attributes of the file. In this research, we explore these issues and show that fine‐grained access control with strong privacy guarantees is practical in the PC. To investigate the potential practicality, we took our fully fledged open source implementation of a PC system and extended it to support fine‐grained private data sharing through attribute‐based encryption. The result was the first design and implementation of a file synchronization service, called StackSync, where the user retains complete control over his or her own data when sharing it. Never before, attribute‐based encryption had been implemented and tested on a real PC service. Our results show that StackSync is both secure and efficient for the PC.
The design of elastic file synchronization services like Dropbox is an open and complex issue yet not unveiled by the major commercial providers, as it includes challenges like fine-grained programmable elasticity and efficient change notification to millions of devices. In this paper, we propose a novel architecture for file synchronization which aims to solve the above two major challenges. At the heart of our proposal lies ObjectMQ, a lightweight framework for providing programmatic elasticity to distributed objects using messaging. The efficient use of indirect communication: i) enables programmatic elasticity based on queue message processing, ii) simplifies change notifications offering simple unicast and multicast primitives; and iii) provides transparent load balancing based on queues.Our reference implementation is StackSync, an open source elastic file synchronization Cloud service developed in the context of the FP7 project CloudSpaces. StackSync supports both predictive and reactive provisioning policies on top of ObjectMQ that adapt to real traces from the Ubuntu One service. The feasibility of our approach has been extensively validated with an open benchmark, including commercial synchronization services like Dropbox or OneDrive.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.