2015. 2nd Issue

Table of contents 

Full issue  (4MB)



M. Horváth
Attribute-Based Encryption Optimized for Cloud Computing 
In this work, we aim to make attribute-based encryption (ABE) more suitable for access control to data stored in the cloud. For this purpose, we concentrate on giving to the encryptor full control over the access rights, providing feasible key management even in case of multiple independent authorities, and enabling viable user revocation, which is essential in practice. Our main result is an extension of the decentralized CP-ABE scheme of Lewko and Waters [8] with identity-based user revocation. Our revocation system is made feasible by removing the computational burden of a revocation event from the cloud service provider, at the expense of some permanent, yet acceptable overhead of the encryption and decryption algorithms run by the users. Thus, the computation overhead is distributed over a potentially large number of users, instead of putting it on a single party (e.g., a proxy server), which would easily lead to a performance bottleneck. The formal security proof of our scheme is given in the generic bilinear group and random oracle models.

S. Sharma, J. Singh Lather, and M. Dave
A Novel Framework for Semantic Discovery of Web Services Using Integrated Semantic Model 
Semantic web technology plays a very critical role in the automatic web service discovery by assigning formal semantics to the service descriptions. Practically, it is not feasible to explicitly annotate the formal semantics to millions of existing services. Further, in user context, the request formation for services in semantic web is a complex process as it requires the user to be technically aware of the underlying technologies of the web services, discovery frameworks, description languages and implementation details. In this paper, we propose a semantic framework that enables Web service discovery based on the combination of semantic and syntax information contained in the service profiles. This novel approach for automatic discovery of Web services employs measures of semantic relatedness, Natural Language Processing techniques and information retrieval based statistical models to match a user request. Additionally, we present an efficient semantic matching technique to compute the intra service semantic similarity scores which further facilitates semantic ranking of services. The efficiency of the proposed approach has been demonstrated through experimental evaluations which clearly show that high degree of automation can be achieved with high precision.The results have been further authenticated by providing comparisons with other Information Retrieval based methods.

Z. Novák, Z. Pap
Fairness in Kademlia with Random Node Joins 
Kademlia is among the most prevalent Distributed Hash Table (DHT) protocols in practice. To understand loadbalancing and fairness properties of any DHT system one of the key requirements is to study and understand the zone size distribution of the network. Already existing and well known analytical results in this field are not applicable to Kademlia directly, due to its unique addressing mechanism. We show that a direct connection exists between the size of the zones of a given Kademlia network and the shape parameters of the data structure called PATRICIA trie filled with the overlay addresses of the same network. Then analytical description of the asymptotic properties of the Kademlia zone size distribution is provided based on the existing literature on random binary tries. We compare Kademlia to the Chord DHT, and show that Kademlia provides a fairer zone size distribution. These results can be used to achieve better load balancing in DHT systems.

G. M. Mashkov, E.G. Borisov, A.G. Vladyko, and A.I. Gomonova
The Use of Software-Defined Radio Systems in Multilateral Navigation Radio Systems 
The paper describes an optional application of software-defined radio systems technology in multilateral range finding systems for solving tasks of determining the fly-ing objects coordinates. The design feature of the described system is the use of cooperative processing of range measure-ments aggregate to improve accuracy of object positioning.


H. Ma, D. Zhao, and P. Yuan
Opportunities in Mobile Crowd Sensing 
Mobile crowd sensing is a new paradigm that takes advantage of pervasive mobile devices to efficiently collect data, enabling numerous largescale applications. Human involvement is one of the most important features, and human mobility offers unprecedented opportunities for both sensing coverage and data transmission. In this article, we investigate the opportunistic characteristics of human mobility from the perspectives of both sensing and transmission, and discuss how to exploit these opportunities to collect data efficiently and effectively. We also outline various open issues brought by human involvement in this emerging research area.



Special Issue on Advanced wireless and mobile technologies and services

Special Issue on Smart Cities: Crowdsourcing and M2M Communication for a Connected Society


Guidelines for our Authors

ITU Telecom World Budapest 2015 (x)

Technical Co-Sponsors





National Cooperation Fund, Hungary