Defense against node compromise in sensor network security

Recent advances in electronic and computer technologies lead to wide-spread deployment of wireless sensor networks (WSNs). WSNs have wide range applications, including military sensing and tracking, environment monitoring, smart environments, etc. Many WSNs have mission-critical tasks, such as military applications. Thus, the security issues in WSNs are kept in the foreground among research areas. Compared with other wireless networks, such as ad hoc, and cellular networks, security in WSNs is more complicated due to the constrained capabilities of sensor nodes and the properties of the deployment, such as large scale, hostile environment, etc. Security issues mainly come from attacks. In general, the attacks in WSNs can be classified as external attacks and internal attacks. In an external attack, the attacking node is not an authorized participant of the sensor network. Cryptography and other security methods can prevent some of external attacks. However, node compromise, the major and unique problem that leads to internal attacks, will eliminate all the efforts to prevent attacks. Knowing the probability of node compromise will help systems to detect and defend against it. Although there are some approaches that can be used to detect and defend against node compromise, few of them have the ability to estimate the probability of node compromise. Hence, we develop basic uniform, basic gradient, intelligent uniform and intelligent gradient models for node compromise distribution in order to adapt to different application environments by using probability theory. These models allow systems to estimate the probability of node compromise. Applying these models in system security designs can improve system security and decrease the overheads nearly in every security area. Moreover, based on these models, we design a novel secure routing algorithm to defend against the routing security issue that comes from the nodes that have already been compromised but have not been detected by the node compromise detecting mechanism. The routing paths in our algorithm detour those nodes which have already been detected as compromised nodes or have larger probabilities of being compromised. Simulation results show that our algorithm is effective to protect routing paths from node compromise whether detected or not.

Trust based security mechanisms for wireless sensor networks

Wireless sensor networks are emerging as effective tools in the gathering and dissemination of data. They can be applied in many fields including health, environmental monitoring, home automation and the military. Like all other computing systems it is necessary to include security features, so that security sensitive data traversing the network is protected. However, traditional security techniques cannot be applied to wireless sensor networks. This is due to the constraints of battery power, memory, and the computational capacities of the miniature wireless sensor nodes. Therefore, to address this need, it becomes necessary to develop new lightweight security protocols. This dissertation focuses on designing a suite of lightweight trust-based security mechanisms and a cooperation enforcement protocol for wireless sensor networks. This dissertation presents a trust-based cluster head election mechanism used to elect new cluster heads. This solution prevents a major security breach against the routing protocol, namely, the election of malicious or compromised cluster heads. This dissertation also describes a location-aware, trust-based, compromise node detection, and isolation mechanism. Both of these mechanisms rely on the ability of a node to monitor its neighbors. Using neighbor monitoring techniques, the nodes are able to determine their neighbors’ reputation and trust level through probabilistic modeling. The mechanisms were designed to mitigate internal attacks within wireless sensor networks. The feasibility of the approach is demonstrated through extensive simulations. The dissertation also addresses non-cooperation problems in multi-user wireless sensor networks. A scalable lightweight enforcement algorithm using evolutionary game theory is also designed. The effectiveness of this cooperation enforcement algorithm is validated through mathematical analysis and simulation. This research has advanced the knowledge of wireless sensor network security and cooperation by developing new techniques based on mathematical models. By doing this, we have enabled others to build on our work towards the creation of highly trusted wireless sensor networks. This would facilitate its full utilization in many fields ranging from civilian to military applications.

Modeling security and cooperation in wireless networks using game theory

This research involves the design, development, and theoretical demonstration of models resulting in integrated misbehavior resolution protocols for ad hoc networked devices. Game theory was used to analyze strategic interaction among independent devices with conflicting interests. Packet forwarding at the routing layer of autonomous ad hoc networks was investigated. Unlike existing reputation based or payment schemes, this model is based on repeated interactions. To enforce cooperation, a community enforcement mechanism was used, whereby selfish nodes that drop packets were punished not only by the victim, but also by all nodes in the network. Then, a stochastic packet forwarding game strategy was introduced. Our solution relaxed the uniform traffic demand that was pervasive in other works. To address the concerns of imperfect private monitoring in resource aware ad hoc networks, a belief-free equilibrium scheme was developed that reduces the impact of noise in cooperation. This scheme also eliminated the need to infer the private history of other nodes. Moreover, it simplified the computation of an optimal strategy. The belief-free approach reduced the node overhead and was easily tractable. Hence it made the system operation feasible. Motivated by the versatile nature of evolutionary game theory, the assumption of a rational node is relaxed, leading to the development of a framework for mitigating routing selfishness and misbehavior in Multi hop networks. This is accomplished by setting nodes to play a fixed strategy rather than independently choosing a rational strategy. A range of simulations was carried out that showed improved cooperation between selfish nodes when compared to older results. Cooperation among ad hoc nodes can also protect a network from malicious attacks. In the absence of a central trusted entity, many security mechanisms and privacy protections require cooperation among ad hoc nodes to protect a network from malicious attacks. Therefore, using game theory and evolutionary game theory, a mathematical framework has been developed that explores trust mechanisms to achieve security in the network. This framework is one of the first steps towards the synthesis of an integrated solution that demonstrates that security solely depends on the initial trust level that nodes have for each other.^

The Use of the Military for Law Enforcement Activities in Central America

Faced with the violence, criminality and insecurity now threatening peace and democratic governance in Central America, the region’s governments have decided to use the Armed Forces to carry out actions in response to criminal actions, looking to improve their performance. Although public demand for including the Armed Forces in these functions takes place within a legally legitimate framework, it is motivated by tangible circumstances such as increased levels of violence, delinquency and crime. Despite being coupled with the perception of institutional weakness within the security and judicial system (particularly police) and the recognition of prestige, efficiency, discipline and severity in fulfilling the Armed Forces’ missions, these arguments are insufficient to legitimize the use of the military as a police force. Within this context, this paper reflects on the implications or consequences of the use of the Armed Forces in duties traditionally assigned to the police in the Central American region with the goal of contributing to the debate on this topic taking place in the Americas. To achieve this end, first we will focus on understanding the actual context in which a decision is made to involve the Armed Forces in security duties in the region. Second, we will examine the effects and implications of this decision on the Armed Forces’ relations within their respective societies. Third and finally, considering this is already a reality in the region, this paper will provide recommendations. The main findings of this research, resulting from the application of an analyticaldescriptive and historically based study, are organized in three dimensions: the political dimension, by implication referring to the relationship between the ultimate political authority and the Armed Forces; the social dimension, by implication the opinion of citizens; and other implications not only affecting the structural and cultural organization of armies and police but also the complementary operational framework within a context of comprehensive response by the State. As a main conclusion, it poses there is an environment conducive to the use of the Armed Forces in citizen’s security, in view of the impact of threats provoked by criminal structures of a military nature currently operating in Central America. However, this participation creates an inevitable social and political impact if implemented in isolation or given a political leading role and/or operational autonomy. This participation poses risks to the institutions of the Armed Forces and the police as well. Finally, this paper identifies an urgent need for the Armed Forces’ role to be more clearly defined with regard to security matters, limiting it to threats that impact States’ governability and existence. Nonetheless, Central American States should seek a COMPREHENSIVE response to current crime and violence, using all necessary institutions to confront these challenges, but with defined roles and responsibilities for each and dynamic coordination to complement their actions.

Capabilities of Police and Military Forces in Central America -- A Comparative Analysis of Guatemala, El Salvador, Honduras an d Nicaragua

A difficult transition to a new paradigm of Democratic Security and the subsequent process of military restructuring during the nineties led El Salvador, Honduras, Guatemala and Nicaragua to re-consider their old structures and functions of their armed forces and police agencies. This study compares the institutions in the four countries mentioned above to assess their current condition and response capacity in view of the contemporary security challenges in Central America. This report reveals that the original intention of limiting armies to defend and protect borders has been threatened by the increasing participation of armies in public security. While the strength of armies has been consolidated in terms of numbers, air and naval forces have failed to become strengthened or sufficiently developed to effectively combat organized crime and drug trafficking and are barely able to conduct air and sea operations. Honduras has been the only country that has maintained a proportional distribution of its armed forces. However, security has been in the hands of a Judicial Police, supervised by the Public Ministry. The Honduran Judicial Police has been limited to exercising preventive police duties, prohibited from carrying out criminal investigations. Nicaragua, meanwhile, possesses a successful police force, socially recognized for maintaining satisfactory levels of security surpassing the Guatemalan and El Salvadoran police, which have not achieved similar results despite of having set up a civilian police force separate from the military. El Salvador meanwhile, has excelled in promoting a Police Academy and career professional education, even while not having military attachés in other countries. Regarding budgetary issues, the four countries allocate almost twice the amount of funding on their security budgets in comparison to what is allocated to their defense budgets. However, spending in both areas is low when taking into account each country's GDP as well as their high crime rates. Regional security challenges must be accompanied by a professionalization of the regional armies focused on protecting and defending borders. Therefore, strong institutional frameworks to support the fight against crime and drug trafficking are required. It will require the strengthening of customs, greater control of illicit arms trafficking, investment in education initiatives, creating employment opportunities and facilitating significant improvements in the judicial system, as well as its accessibility to the average citizen.

The Transitioning Economic Dynamics of the Military in Communist Regimes: A Comparison of Cuba, China and Vietnam [Student's Paper Series]

Several factors can increase or decrease military-economic involvement in communist regimes. This anomalous form of military behavior, labeled as the Military Business Complex (MBC), emerged in various communist regimes in the 1980s. However, in early 2000s, the communist governments of China and Vietnam began to decrease the number of military-managed industries, while similar industries increased in Cuba. This paper explains why military industries in Cuba have increased over the last two decades, while they decreased in the Chinese and Vietnamese examples. This question is answered by comparatively testing two hypotheses: the Communist Party and the Bureaucratic-Authoritarian (BA) Hypotheses. The Communist Party hypotheses helps explain how the historical and current structures of Party oversight of the military have been lacking in strength and reliability in Cuba, while they traditionally have been more robust in China and Vietnam. The BA hypotheses helps explain how, due to the lack of a strong civilian institutional oversight, the Cuban military has grown into a bureaucratic entity with many political officers holding autonomous positions of power, an outcome that is not prevalent in the Chinese and Vietnamese examples. Thus, with the establishment of a bureaucratic military government and with the absence of a strong party oversight, the Cuban military has been able to protect its economic endeavors while the Chinese and Vietnamese MBC regimes have contracted.

Building Regional Security: Cooperation in the 21st Century: The Case of the Caribbean Regional Security System [RSS]

Small states that lack capacity and act on their own may fall victim to international and domestic terrorism, transnational organized crime or criminal gangs. The critical issue is not whether small Caribbean states should cooperate in meeting security challenges, but it is rather in what manner, and by which mechanisms can they overcome obstacles in the way of cooperation. The remit of the Regional Security System (RSS) has expanded dramatically, but its capabilities have improved very slowly. The member governments of the RSS are reluctant to develop military capacity beyond current levels since they see economic and social development and disaster relief as priorities, requiring little investment in military hardware. The RSS depends on international donors such as the USA, Canada, Great Britain, and increasingly China to fund training programs, maintain equipment and acquire material. In the view of most analysts, an expanded regional arrangement based on an RSS nucleus is not likely in the foreseeable future. Regional political consensus remains elusive and the predominance of national interests over regional considerations continues to serve as an obstacle to any CARICOM wide regional defense mechanism. Countries in the Caribbean, including the members of the RSS, have to become more responsible for their own security from their own resources. While larger CARICOM economies can do this, it would be difficult for most OECS members of the RSS to do the same. The CARICOM region including the RSS member countries, have undertaken direct regional initiatives in security collaboration. Implementation of the recommendations of the Regional Task Force on Crime and Security (RTFCS) and the structure and mechanisms created for the staging of the Cricket World Cup (CWC 2007) resulted in unprecedented levels of cooperation and permanent legacy institutions for the regional security toolbox. The most important tier of security relationships for the region is the United States and particularly USSOUTHCOM. The Caribbean Basin Security Initiative [CBSI] in which the countries of the RSS participate is a useful U.S. sponsored tool to strengthen the capabilities of the Caribbean countries and promote regional ownership of security initiatives. Future developments under discussion by policy makers in the Caribbean security environment include the granting of law enforcement authority to the military, the formation of a single OECS Police Force, and the creation of a single judicial and law enforcement space. The RSS must continue to work with its CARICOM partners, as well as with the traditional “Atlantic Powers” particularly Canada, the United States and the United Kingdom to implement a general framework for regional security collaboration. Regional security cooperation should embrace wider traditional and non-traditional elements of security appropriate to the 21st century. Security cooperation must utilize to the maximum the best available institutions, mechanisms, techniques and procedures already available in the region. The objective should not be the creation of new agencies but rather the generation of new resources to take effective operations to higher cumulative levels. Security and non-security tools should be combined for both strategic and operational purposes. Regional, hemispheric, and global implications of tactical and operational actions must be understood and appreciated by the forces of the RSS member states. The structure and mechanisms, created for the staging of Cricket World Cup 2007 should remain as legacy institutions and a toolbox for improving regional security cooperation in the Caribbean. RSS collaboration should build on the process of operational level synergies with traditional military partners. In this context, the United States must be a true partner with shared interests, and with the ability to work unobtrusively in a nationalistic environment. Withdrawal of U.S. support for the RSS is not an option.

Innovating from the War Economy: Formal, Informal, and Illicit Economic Activities of the Military in Colombia

Over the last decade, the Colombian military has successfully rolled back insurgent groups, cleared and secured conflict zones, and enabled the extraction of oil and other key commodity exports. As a result, official policies of both the Uribe and Santos governments have promoted the armed forces to participate to an unprecedented extent in economic activities intended to consolidate the gains of the 2000s. These include formal involvement in the economy, streamlined in a consortium of military enterprises and social foundations that are intended to put the Colombian defense sector “on the map” nationally and internationally, and informal involvement expanded mainly through new civic action development projects intended to consolidate the security gains of the 2000s. However, failure to roll back paramilitary groups other than through the voluntary amnesty program of 2005 has facilitated the persistence of illicit collusion by military forces with reconstituted “neoparamilitary” drug trafficking groups. It is therefore crucially important to enhance oversight mechanisms and create substantial penalties for collusion with illegal armed groups. This is particularly important if Colombia intends to continue its new practice of exporting its security model to other countries in the region. The Santos government has initiated several promising reforms to enhance state capacity, institutional transparence, and accountability of public officials to the rule of law, which are crucial to locking in security gains and revitalizing democratic politics. Efforts to diminish opportunities for illicit association between the armed forces and criminal groups should complement that agenda, including the following: Champion breaking existing ties between the military and paramilitary successor groups through creative policies involving a mixture of punishments and rewards directed at the military; Investigation and extradition proceedings of drug traffickers, probe all possible ties, including as a matter of course the possibility of Colombian military collaboration. Doing so rigorously may have an important effect deterring military collusion with criminal groups. Establish and enforce zero-tolerance policies at all military ranks regarding collusion with criminal groups; Reward military units that are effective and also avoid corruption and criminal ties by providing them with enhanced resources and recognition; Rely on the military for civic action and development assistance as minimally as possible in order to build long-term civilian public sector capacity and to reduce opportunities for routine exposure of military forces to criminal groups circulating in local populations.

South American Defense Council: What it Means for Regional Security?

The South American Defense Council (CSD), created in March 2009 as a military coordinating body of the Union of South American Nations (UNASUR) demonstrates a growing trend among Latin American countries to approach matters of regional security independent of the United States. The CSD also indicates a maturation of democratic civil military relations in a region once dominated by authoritarian military regimes. The CSD aims to facilitate the exchange of information about regional defense policies, promote collaboration for disaster relief, and promote civil-military engagement. In less than a year it is hardly a tested entity, but the presence of 12 South American states coming together around security policy marks an important moment in the evolution of civil-military relations in the region. Brazil has taken on an important leadership role in the CSD, acting as a leader in recent regional peacekeeping efforts. As a geopolitical move, Brazil also sees a benefit in promoting good relationships with all countries of South america, given its common border with nine of them. Although the United States is not a member of the CSD, the organization's agenda of infromation exchange of defense policies, military cooperation, and capacity building, including disaster assistance and preparedness provide opportunities for greater collaboration. The CSD is not part of the Inter-American System created after the Second World War. It is unclear how its work will coincide with the OAS Committee on Hemispheric Security or its Secretariat for Multidimensional Security. The U.S. should view the CSD as a mechanism to promote joint initiatives that encourage democratic governance in the region.

Altered Landscape or Arms Race? Making Sense of Military Spending in South America

In 2009, South American military spending reached a total of $51.8 billion, a fifty percent increased from 2000 expenditures. The five-year moving average of arms transfers to South America was 150 percent higher from 2005 to 2009 than figures for 2000 to 2004.[1] These figures and others have led some observers to conclude that Latin America is engaged in an arms race. Other reasons, however, account for Latin America’s large military expenditure. Among them: Several countries have undertaken long-prolonged modernization efforts, recently made possible by six years of consistent regional growth.[2] A generational shift is at hand. Armed Forces are beginning to shed the stigma and association with past dictatorial regimes.[3] Countries are pursuing specific individual strategies, rather than reacting to purchases made by neighbors. For example, Brazil wants to attain greater control of its Amazon rainforests and offshore territories, Colombia’s spending demonstrates a response to internal threats, and Chile is continuing a modernization process begun in the 1990s.[4] Concerns remain, however: Venezuela continues to demonstrate poor democratic governance and a lack of transparency; neighbor-state relations between Colombia and Venezuela, Peru and Chile, and Bolivia and Paraguay, must all continue to be monitored; and Brazil’s military purchases, although legitimate, will likely result in a large accumulation of equipment.[5] These concerns can be best addressed by strengthening and garnering greater participation in transparent procurement mechanism.[6] The United States can do its part by supporting Latin American efforts to embrace the transparency process. _________________ [1] Bromley, Mark, “An Arms Race in Our Hemisphere? Discussing the Trends and Implications of Military Expenditures in South America,” Brookings Institution Conference, Washington, D.C., June 3rd, 2010, Transcript Pgs. 12,13, and 16 [2] Robledo, Marcos, “The Rearmament Debate: A Chilean Perspective,” Power Point presentation, slide 18, 2010 Western Hemisphere Security Colloquium, Miami, Florida, May 25th-26th, 2010 [3] Yopo, Boris, “¿Carrera Armamentista en la Regiόn?” La Tercera, November 2nd, 2009, http://www.latercera.com/contenido/895_197084_9.shtml, accessed October 8th, 2010 [4] Walser, Ray, “An Arms Race in Our Hemisphere? Discussing the Trends and Implications of Military Expenditures in South America,” Brookings Institution Conference, Washington, D.C., June 3rd, 2010, Transcript Pgs. 49,50,53 and 54 [5] Ibid., Guevara, Iñigo, Pg. 22 [6] Ibid., Bromley, Mark, Pgs. 18 and 19

Defense Against Node Compromise in Sensor Network Security

Recent advances in electronic and computer technologies lead to wide-spread deployment of wireless sensor networks (WSNs). WSNs have wide range applications, including military sensing and tracking, environment monitoring, smart environments, etc. Many WSNs have mission-critical tasks, such as military applications. Thus, the security issues in WSNs are kept in the foreground among research areas. Compared with other wireless networks, such as ad hoc, and cellular networks, security in WSNs is more complicated due to the constrained capabilities of sensor nodes and the properties of the deployment, such as large scale, hostile environment, etc. Security issues mainly come from attacks. In general, the attacks in WSNs can be classified as external attacks and internal attacks. In an external attack, the attacking node is not an authorized participant of the sensor network. Cryptography and other security methods can prevent some of external attacks. However, node compromise, the major and unique problem that leads to internal attacks, will eliminate all the efforts to prevent attacks. Knowing the probability of node compromise will help systems to detect and defend against it. Although there are some approaches that can be used to detect and defend against node compromise, few of them have the ability to estimate the probability of node compromise. Hence, we develop basic uniform, basic gradient, intelligent uniform and intelligent gradient models for node compromise distribution in order to adapt to different application environments by using probability theory. These models allow systems to estimate the probability of node compromise. Applying these models in system security designs can improve system security and decrease the overheads nearly in every security area. Moreover, based on these models, we design a novel secure routing algorithm to defend against the routing security issue that comes from the nodes that have already been compromised but have not been detected by the node compromise detecting mechanism. The routing paths in our algorithm detour those nodes which have already been detected as compromised nodes or have larger probabilities of being compromised. Simulation results show that our algorithm is effective to protect routing paths from node compromise whether detected or not.

Trust Based Security Mechanisms for Wireless Sensor Networks

Wireless sensor networks are emerging as effective tools in the gathering and dissemination of data. They can be applied in many fields including health, environmental monitoring, home automation and the military. Like all other computing systems it is necessary to include security features, so that security sensitive data traversing the network is protected. However, traditional security techniques cannot be applied to wireless sensor networks. This is due to the constraints of battery power, memory, and the computational capacities of the miniature wireless sensor nodes. Therefore, to address this need, it becomes necessary to develop new lightweight security protocols. This dissertation focuses on designing a suite of lightweight trust-based security mechanisms and a cooperation enforcement protocol for wireless sensor networks. This dissertation presents a trust-based cluster head election mechanism used to elect new cluster heads. This solution prevents a major security breach against the routing protocol, namely, the election of malicious or compromised cluster heads. This dissertation also describes a location-aware, trust-based, compromise node detection, and isolation mechanism. Both of these mechanisms rely on the ability of a node to monitor its neighbors. Using neighbor monitoring techniques, the nodes are able to determine their neighbors’ reputation and trust level through probabilistic modeling. The mechanisms were designed to mitigate internal attacks within wireless sensor networks. The feasibility of the approach is demonstrated through extensive simulations. The dissertation also addresses non-cooperation problems in multi-user wireless sensor networks. A scalable lightweight enforcement algorithm using evolutionary game theory is also designed. The effectiveness of this cooperation enforcement algorithm is validated through mathematical analysis and simulation. This research has advanced the knowledge of wireless sensor network security and cooperation by developing new techniques based on mathematical models. By doing this, we have enabled others to build on our work towards the creation of highly trusted wireless sensor networks. This would facilitate its full utilization in many fields ranging from civilian to military applications.