Trust and Privacy in Development of Publish/Subscribe Systems

Publish/subscribe (pub/sub) is a widely deployed paradigm for information dissemination in a variety of distributed applications such as financial platforms, e-health frameworks and the Internet-of-Things. In essence, the pub/sub model considers one or more publishers generating feeds of information and a set of subscribers, the clients of the system. A pub/sub service is in charge of delivering the published information to interested clients. With the advent of cloud computing, we observe a growing tendency to externalize applications using pub/sub services to public clouds. This trend, despite its advantages, opens up multiple important data privacy and trust issues. Although multiple solutions for data protection have been proposed by the academic community, there is no unified view or framework describing how to deploy secure pub/sub systems on public clouds. To remediate this, we advocate towards a trust model which we believe can serve as basis for such deployments

Secure Broker-Less Publish/Subscribe Systems Using Identity-Based Encryption

publish–subscribe is a messaging pattern where senders of messages, called publishers, do not program the messages to be sent directly to specific receivers, called subscribers. provisioning of basic security mechanisms such as authentication and confidentiality is highly challenging in a content based publish/subscribe system. Authentication of publishers and subscribers is difficult to achieve due to the loose coupling of publishers and subscribers. Likewise, confidentiality of events and subscriptions conflicts with content-based routing. This paper presents a novel approach to provide confidentiality and authentication in a broker-less content-based publish/subscribe system. The authentication of publishers and subscribers as well as confidentiality of events is ensured, by adapting the pairing-based cryptography mechanisms, to the needs of a publish/subscribe system. Furthermore, an algorithm to cluster subscribers according to their subscriptions preserves a weak notion of subscription confidentiality. In addition to our previous work [20], this paper contributes 1) use of searchable encryption to enable efficient routing of encrypted events, 2) multicredential routing a new event dissemination strategy to strengthen the weak subscription confidentiality, and 3) thorough analysis of different attacks on subscription confidentiality. The overall approach provides fine-grained key management and the cost for encryption, decryption, and routing is in the order of subscribed attributes. Moreover, the evaluations show that providing security is affordable w.r.t. 1) throughput of the proposed cryptographic primitives, and 2) delays incurred during the construction of the publish/subscribe overlay and the event dissemination

PRE+: dual of proxy re-encryption for secure cloud data sharing service

With the rapid development of very large, diverse, complex, and distributed datasets generated from internet transactions, emails, videos, business information systems, manufacturing industry, sensors and internet of things etc., cloud and big data computation have emerged as a cornerstone of modern applications. Indeed, on the one hand, cloud and big data applications are becoming a main driver for economic growth. On the other hand, cloud and big data techniques may threaten people and enterprises’ privacy and security due to ever increasing exposure of their data to massive access. In this paper, aiming at providing secure cloud data sharing services in cloud storage, we propose a scalable and controllable cloud data sharing framework for cloud users (called: Scanf). To this end, we introduce a new cryptographic primitive, namely, PRE+, which can be seen as the dual of traditional proxy re-encryption (PRE) primitive. All the traditional PRE schemes until now require the delegator (or the delegator and the delegatee cooperatively) to generate the re-encryption keys. We observe that this is not the only way to generate the re-encryption keys, the encrypter also has the ability to generate re-encryption keys. Based on this observation, we construct a new PRE+ scheme, which is almost the same as the traditional PRE scheme except the re-encryption keys generated by the encrypter. Compared with PRE, our PRE+ scheme can easily achieve the non-transferable property and message-level based fine-grained delegation. Thus our Scanf framework based on PRE+ can also achieve these two properties, which is very important for users of cloud storage sharing service. We also roughly evaluate our PRE+ scheme’s performance and the results show that our scheme is efficient and practica for cloud data storage applications.Peer ReviewedPostprint (author's final draft

Scalable security and accounting services for content-based publish/subscribe systems

Content-based publish/subscribe systems offer an interaction scheme that is appropriate for a variety of large scale dynamic applications. However, widespread use of these systems is hindered by a lack of suitable security services. In this paper we present scalable solutions for confidentiality, integrity, and authentication for these systems. We also provide verifiable usagebased accounting services, which are required for e-commerce and e-business applications that use publish/subscribe systems. Our solutions are applicable in a setting where publishers and subscribers may not trust the publish/subscribe infrastructure. Keywords: Publish/subscribe systems, Electronic Commerce, Securit

Confidentiality-Preserving Publish/Subscribe: A Survey

Publish/subscribe (pub/sub) is an attractive communication paradigm for large-scale distributed applications running across multiple administrative domains. Pub/sub allows event-based information dissemination based on constraints on the nature of the data rather than on pre-established communication channels. It is a natural fit for deployment in untrusted environments such as public clouds linking applications across multiple sites. However, pub/sub in untrusted environments lead to major confidentiality concerns stemming from the content-centric nature of the communications. This survey classifies and analyzes different approaches to confidentiality preservation for pub/sub, from applications of trust and access control models to novel encryption techniques. It provides an overview of the current challenges posed by confidentiality concerns and points to future research directions in this promising field

Towards a secure cooperation mechanism for Challenging Networks

A Challenging Network (CN) is a network paradigm adapting to the many issues of the environment in order to guarantee the communication among nodes. One of the most important issues of a CN is the problem of secure cooperation among nodes. In fact, an attacker, either internal or external, may constitute a threat for the network. In this work I investigate the problem of secure cooperation in three kinds of CNs: the Underwater Acoustic Net- works (UANs), the Delay Tolerant Networks (DTNs) and the Publish/Subscribe Networks (PSNs). A UAN is a network paradigm allowing communication among underwater nodes equipped with acoustic modems. Since the acoustic channel is an open medium, an attacker conveniently equipped could intercept the messages traversing the network. In this work I describe a cryptographic suite, aimed at protecting the communication among underwater acoustic nodes. A DTN is a network paradigm guaranteeing message delivery even in presence of network partitions. A DTN relies on the implicit assumption that nodes cooperate towards message forwarding. However, this assumption cannot be satisfied when there are malicious nodes acting as blackholes and voluntarily attracting and dropping messages. In this work I propose a reputation-based protocol for contrasting blackholes. A PSN is a network paradigm allowing communication from publishers to subscribers by means of an infrastructure, called Dispatcher. In this work I present a secure PSN conceived to support cooperation be- tween organizations. The service is based on the notion of security group, an overlay composed of brokers representing organizations that guarantees confidentiality and integrity in end-to-end delivery of messages and supports clients mobility

Privacy aware key establishment for publish/subscribe infrastructures in Ubiquitous environments

Ubiquitous Computing, UbiComp, is a vision of embedding computing to every aspect of our day to day life. In ubiquitous computing, interaction among communicating entities exists in highly dynamic, large scale and failure prone environments. Publish/Subscribe interaction paradigm, Pub/Sub, can be used to decouple interacting entities in ubiquitous environments by delivering events based on users interests. In this scenario, securing events dissemination and protecting users' privacy are essential requirements for ubiquitous applications. In this thesis, we propose an encryption key establishment scheme for encrypting disseminated events in ubiquitous Pub/Sub infrastructures. The proposed key establishment scheme considers the dynamism, scalability and failure tolerance issues of ubiquitous environments. More importantly, the generated encryption keys reflect multi level access control polices, which is important to enforce users' privacy polices