310 research outputs found
A Survey on Confidentiality and Authentication in Content Based Publish/Subscribe System
The basic security mechanism such as authentication and confidentiality is highly challenging in a content based publish/subscribe system. Authentication of publisher and subscribers is difficult to achieve due to loose coupling of publisher and subscriber. The authentication and confidentiality of publisher and subscribers of events ensured by adapting the pairing based cryptography mechanism. Furthermore, an algorithm to cluster subscriber according to their subscriptions preserves a weak notion of subscription confidentiality.
DOI: 10.17762/ijritcc2321-8169.150519
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
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
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
Certificate Based Encryption for Securing Broker-Less Publish/Subscribe System in Wireless Network
ABSTRACT: The security mechanisms such as authentication and confidentiality is highly challenging in a contentbased publish/subscribe system and due to the loose coupling of publishers and subscribers, authentication and confidentiality of publishers and subscribers is difficult to achieve. In particular content-based approaches in brokerless environments do not address confidentiality at all. This paper presents to provide confidentiality and authentication in a broker-less content-based publish-subscribe system. The authentication and confidentiality and other security approach of publishers and subscribers ensured, by adapting the certificate based encryption mechanism. In certificate based encryption signature not only acts as certificate but also as encrypt and decrypt key. To encrypt or to decrypt a message, a key holder needs both its public key and private key and an up-to-date certificate from an authorizer. Certificate-based encryption combines the best aspects of identity-based encryption and public key encryption. This mechanism describes how certificate-based encryption can be used to construct an efficient PKI requiring fewer infrastructures than any previous method
Privacy Preserving Enforcement of Sensitive Policies in Outsourced and Distributed Environments
The enforcement of sensitive policies in untrusted environments is still an
open challenge for policy-based systems. On the one hand, taking any
appropriate security decision requires access to these policies. On the other
hand, if such access is allowed in an untrusted environment then confidential
information might be leaked by the policies. The key challenge is how to
enforce sensitive policies and protect content in untrusted environments. In
the context of untrusted environments, we mainly distinguish between outsourced
and distributed environments. The most attractive paradigms concerning
outsourced and distributed environments are cloud computing and opportunistic
networks, respectively.
In this dissertation, we present the design, technical and implementation
details of our proposed policy-based access control mechanisms for untrusted
environments. First of all, we provide full confidentiality of access policies
in outsourced environments, where service providers do not learn private
information about policies. We support expressive policies and take into
account contextual information. The system entities do not share any encryption
keys. For complex user management, we offer the full-fledged Role-Based Access
Control (RBAC) policies.
In opportunistic networks, we protect content by specifying expressive
policies. In our proposed approach, brokers match subscriptions against
policies associated with content without compromising privacy of subscribers.
As a result, unauthorised brokers neither gain access to content nor learn
policies and authorised nodes gain access only if they satisfy policies
specified by publishers. Our proposed system provides scalable key management
in which loosely-coupled publishers and subscribers communicate without any
prior contact. Finally, we have developed a prototype of the system that runs
on real smartphones and analysed its performance.Comment: Ph.D. Dissertation. http://eprints-phd.biblio.unitn.it/1124
Principles of building scalable and robust event-based systems
Event-based systems are of tremendous importance for a wide range of distributed applications interacting with physical processes, e.g., traffic management, financial services, manufacturing processes, or health services. Event-based systems support to monitor, analyze events of interest efficiently. Therefore, they enable distributed applications to respond to detected events in the form of appropriate actions. Event-based systems provide as part of the publish/subscribe paradigm, mechanisms for the scalable integration of a variety of information sources, e.g., dedicated sensor networks, mobile devices, or cameras. In addition, event-based systems allow as part of the event processing paradigm to detect correlations between events from distinct information sources. Event-based systems ensure two important forms of decoupling of importance building scalable distributed applications. Decoupling producers of information and consumers of information by ensuring that neither producers need to keep state on the interested consumers nor consumers need to know the producers of information, is a key principle for scalable communications. Furthermore, a step-wise correlation from primary events to events of importance for distributed applications is an enabler to specify distributed applications independent from the underlying sensor infrastructure at hand.
In this thesis, we present and discuss principles of building scalable and robust event-based systems. On the one hand, this requires distributed mechanisms to fulfill a wide spectrum of distinct application requirements, e.g., being bandwidth efficient and providing events with low end-to-end latency. On the other hand, the underlying mechanisms for event-based systems need to deal with many levels of dynamics, e. g., dynamics in the rate at which events are produced, dynamics in the interest of producers and consumers, mobility of consumer and producer, failures and changing security privileges to access events. In the context of mechanisms for event distribution, operator execution, operator migration, operator recovery and secure access to events, we highlight problems in the scalable and robust design of those mechanisms. We give an overview on related work in the field and present in a tutorial manner the ideas of six own contributions for realizing distributed event-based systems
Contributions to the privacy provisioning for federated identity management platforms
Identity information, personal data and user’s profiles are key assets for organizations
and companies by becoming the use of identity management (IdM) infrastructures a prerequisite
for most companies, since IdM systems allow them to perform their business
transactions by sharing information and customizing services for several purposes in more
efficient and effective ways.
Due to the importance of the identity management paradigm, a lot of work has been done
so far resulting in a set of standards and specifications. According to them, under the
umbrella of the IdM paradigm a person’s digital identity can be shared, linked and reused
across different domains by allowing users simple session management, etc. In this way,
users’ information is widely collected and distributed to offer new added value services
and to enhance availability. Whereas these new services have a positive impact on users’
life, they also bring privacy problems.
To manage users’ personal data, while protecting their privacy, IdM systems are the ideal
target where to deploy privacy solutions, since they handle users’ attribute exchange.
Nevertheless, current IdM models and specifications do not sufficiently address comprehensive
privacy mechanisms or guidelines, which enable users to better control over the
use, divulging and revocation of their online identities. These are essential aspects, specially
in sensitive environments where incorrect and unsecured management of user’s data
may lead to attacks, privacy breaches, identity misuse or frauds.
Nowadays there are several approaches to IdM that have benefits and shortcomings, from
the privacy perspective.
In this thesis, the main goal is contributing to the privacy provisioning for federated
identity management platforms. And for this purpose, we propose a generic architecture
that extends current federation IdM systems. We have mainly focused our contributions
on health care environments, given their particularly sensitive nature. The two main
pillars of the proposed architecture, are the introduction of a selective privacy-enhanced
user profile management model and flexibility in revocation consent by incorporating an
event-based hybrid IdM approach, which enables to replace time constraints and explicit
revocation by activating and deactivating authorization rights according to events. The
combination of both models enables to deal with both online and offline scenarios, as well
as to empower the user role, by letting her to bring together identity information from
different sources.
Regarding user’s consent revocation, we propose an implicit revocation consent mechanism
based on events, that empowers a new concept, the sleepyhead credentials, which
is issued only once and would be used any time. Moreover, we integrate this concept
in IdM systems supporting a delegation protocol and we contribute with the definition
of mathematical model to determine event arrivals to the IdM system and how they are
managed to the corresponding entities, as well as its integration with the most widely
deployed specification, i.e., Security Assertion Markup Language (SAML).
In regard to user profile management, we define a privacy-awareness user profile management
model to provide efficient selective information disclosure. With this contribution a
service provider would be able to accesses the specific personal information without being
able to inspect any other details and keeping user control of her data by controlling
who can access. The structure that we consider for the user profile storage is based on
extensions of Merkle trees allowing for hash combining that would minimize the need of
individual verification of elements along a path. An algorithm for sorting the tree as we
envision frequently accessed attributes to be closer to the root (minimizing the access’
time) is also provided.
Formal validation of the above mentioned ideas has been carried out through simulations
and the development of prototypes. Besides, dissemination activities were performed in
projects, journals and conferences.Programa Oficial de Doctorado en IngenierĂa TelemáticaPresidente: MarĂa Celeste Campo Vázquez.- Secretario: MarĂa Francisca Hinarejos Campos.- Vocal: Ă“scar Esparza MartĂ
2013 Doctoral Workshop on Distributed Systems
The Doctoral Workshop on Distributed Systems was held at Les Plans-sur-Bex, Switzerland, from June 26-28, 2013. Ph.D. students from the Universities of Neuchâtel and Bern as well as the University of Applied Sciences of Fribourg presented their current research work and discussed recent research results. This technical report includes the extended abstracts of the talks given during the workshop
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