SECURITY, PRIVACY AND APPLICATIONS IN VEHICULAR AD HOC NETWORKS

With wireless vehicular communications, Vehicular Ad Hoc Networks (VANETs) enable numerous applications to enhance traffic safety, traffic efficiency, and driving experience. However, VANETs also impose severe security and privacy challenges which need to be thoroughly investigated. In this dissertation, we enhance the security, privacy, and applications of VANETs, by 1) designing application-driven security and privacy solutions for VANETs, and 2) designing appealing VANET applications with proper security and privacy assurance. First, the security and privacy challenges of VANETs with most application significance are identified and thoroughly investigated. With both theoretical novelty and realistic considerations, these security and privacy schemes are especially appealing to VANETs. Specifically, multi-hop communications in VANETs suffer from packet dropping, packet tampering, and communication failures which have not been satisfyingly tackled in literature. Thus, a lightweight reliable and faithful data packet relaying framework (LEAPER) is proposed to ensure reliable and trustworthy multi-hop communications by enhancing the cooperation of neighboring nodes. Message verification, including both content and signature verification, generally is computation-extensive and incurs severe scalability issues to each node. The resource-aware message verification (RAMV) scheme is proposed to ensure resource-aware, secure, and application-friendly message verification in VANETs. On the other hand, to make VANETs acceptable to the privacy-sensitive users, the identity and location privacy of each node should be properly protected. To this end, a joint privacy and reputation assurance (JPRA) scheme is proposed to synergistically support privacy protection and reputation management by reconciling their inherent conflicting requirements. Besides, the privacy implications of short-time certificates are thoroughly investigated in a short-time certificates-based privacy protection (STCP2) scheme, to make privacy protection in VANETs feasible with short-time certificates. Secondly, three novel solutions, namely VANET-based ambient ad dissemination (VAAD), general-purpose automatic survey (GPAS), and VehicleView, are proposed to support the appealing value-added applications based on VANETs. These solutions all follow practical application models, and an incentive-centered architecture is proposed for each solution to balance the conflicting requirements of the involved entities. Besides, the critical security and privacy challenges of these applications are investigated and addressed with novel solutions. Thus, with proper security and privacy assurance, these solutions show great application significance and economic potentials to VANETs. Thus, by enhancing the security, privacy, and applications of VANETs, this dissertation fills the gap between the existing theoretic research and the realistic implementation of VANETs, facilitating the realistic deployment of VANETs

Privatization in Sub-Saharan Africa: Some Lessons from Experiences to Date

Privatization became a central element of economic reforms in most countries in Sub-Saharan Africa during the 1990s. Yet, empirical evidence regarding the impact of privatization remains scarce. Since the seminal work of CAMPBELL-WHITE & BHATIA [1998], covering transactions on the African continent until 1996, no comprehensive assessment has been conducted. At a time when public opposition to further privatization is growing, this paper aims at giving a broad overview of the impact of privatization in Sub-Saharan Africa from 1991 to 2002 in the light of recent developments, and to derive some general trends and conclusions from the body of empirical evidence available to date. During this period, about 2300 privatization transactions have taken place, generating a total sales value estimated at US$ 9 billion. The main findings on the impact of privatization are as follows: first, privatization has had a minimal one-off impact on the budget; second, firm turnover and profitability have generally increased immediately following privatization but the evidence is mixed regarding the sustainability of the initial post-privatization upswing; third, employment has been adversely affected by privatization, although the latter has not resulted in massive layoffs in absolute terms; fourth, FDI and stock markets have played a limited role in privatization transactions despite some showcase transactions; fifth, regulation and competition have often been overlooked in the privatization process, and even where they have been dealt with, enforcement problems have greatly limited their effectiveness; sixth, privatization has created new political patronage opportunities, leading to numerous corruption scandals which have damaged the credibility of the privatization process; finally, social aspects of privatizations have generally been overlooked, reflecting the tendency to focus on privatization transactions, rather than on sector reorganization at large including wider social objectives.Africa, competition, governance, privatization, regulation

Improved search methods for assessing Delay-Tolerant Networks vulnerability to colluding strong heterogeneous attacks

Increasingly more digital communication is routed among wireless, mobile computers over ad-hoc, unsecured communication channels. In this paper, we design two stochastic search algorithms (a greedy heuristic, and an evolutionary algorithm) which automatically search for strong insider attack methods against a given ad-hoc, delay-tolerant communication protocol, and thus expose its weaknesses. To assess their performance, we apply the two algorithms to two simulated, large-scale mobile scenarios (of different route morphology) with 200 nodes having free range of movement. We investigate a choice of two standard attack strategies (dropping messages and flooding the network), and four delay-tolerant routing protocols: First Contact, Epidemic, Spray and Wait, and MaxProp. We find dramatic drops in performance: replicative protocols (Epidemic, Spray and Wait, MaxProp), formerly deemed resilient, are compromised to different degrees (delivery rates between 24% and 87%), while a forwarding protocol (First Contact) is shown to drop delivery rates to under 5% — in all cases by well-crafted attack strategies and with an attacker group of size less than 10% the total network size. Overall, we show that the two proposed methods combined constitute an effective means to discover (at design-time) and raise awareness about the weaknesses and strengths of existing ad-hoc, delay-tolerant communication protocols against potential malicious cyber-attacks

Strategy for Economic Reform in West Bengal

During the last two decades West Bengal has led the rest of the country with regard to agricultural performance and implementation of panchayat institutions. But these developments have begun to level out. At the same time the state has fallen behind in other sectors--industry, higher education and state of public finances, particularly--to an extent that is seriously worrying. This paper reviews performance of these different sectors, discusses possible explanatory factors, and makes a number of suggestions for policy reforms. With regard to industrial revival, it stresses public investment in transport and communication, measures to improve higher education, foster industry-university collaborations, and help smallscale industries overcome specific market imperfections (access to credit, technology and distribution channels). In public finance, emphasis is placed on raising tax revenues (especially with regard to the service sector), limiting losses of public sector undertakings, and widening the scope of land taxes and user fees. In the agricultural sector, the need for a greater role of the government with regard to biotechnology, extension services, irrigation and flood control is emphasised, along with suggestions for encouraging and regulating contract farming with MNCs. Finally the article urges greater empowerment of panchayats with regard to social service delivery and agro-business development, and administrative reforms to enhance accountability of state government employees.

Dynamic services in mobile ad hoc networks

The increasing diffusion of wireless-enabled portable devices is pushing toward the design of novel service scenarios, promoting temporary and opportunistic interactions in infrastructure-less environments. Mobile Ad Hoc Networks (MANET) are the general model of these higly dynamic networks that can be specialized, depending on application cases, in more specific and refined models such as Vehicular Ad Hoc Networks and Wireless Sensor Networks. Two interesting deployment cases are of increasing relevance: resource diffusion among users equipped with portable devices, such as laptops, smart phones or PDAs in crowded areas (termed dense MANET) and dissemination/indexing of monitoring information collected in Vehicular Sensor Networks. The extreme dynamicity of these scenarios calls for novel distributed protocols and services facilitating application development. To this aim we have designed middleware solutions supporting these challenging tasks. REDMAN manages, retrieves, and disseminates replicas of software resources in dense MANET; it implements novel lightweight protocols to maintain a desired replication degree despite participants mobility, and efficiently perform resource retrieval. REDMAN exploits the high-density assumption to achieve scalability and limited network overhead. Sensed data gathering and distributed indexing in Vehicular Networks raise similar issues: we propose a specific middleware support, called MobEyes, exploiting node mobility to opportunistically diffuse data summaries among neighbor vehicles. MobEyes creates a low-cost opportunistic distributed index to query the distributed storage and to determine the location of needed information. Extensive validation and testing of REDMAN and MobEyes prove the effectiveness of our original solutions in limiting communication overhead while maintaining the required accuracy of replication degree and indexing completeness, and demonstrates the feasibility of the middleware approach