Like conventional networks, security is also a big concern in wireless sensor networks. However, security in this type of networks faces not only typical but also new challenges. Constrained devices, changing topology or susceptibility to unprecedented security threats such as node capture and node compromise has refrained developers from applying conventional security solutions into wireless sensor networks. Hence, developing security solutions for wireless sensor networks not only requires well security analysis but also offers a low power and processing consuming.In this thesis, we implemented security solution targeting IRIS sensor motes. In our implementation, a public key-based key exchange is used to establish shared secret keys between sensor nodes. These secret keys are used to provide authenticity, integrity and freshness for transmission data. Our implementation ensures the flexibility in integrating our solution with available TinyOS operating system. Additionally, the thesis work also focuses on evaluating the performance in wireless sensor networks both in memory and energy consuming.

Hybrid optical packet/circuit switched networking architectures are increasingly becoming an interesting research field. They integrate and combine the high resource utilization of statistically multiplexed packet switched networks with the low processing requirements and guaranteed quality of service provided by circuit switched networks. The aim of this thesis is to integrate the OpMiGua hybrid optical network with Ethernet. Specifically, the work is focused on the compatibility of the Ethernet’s loop-free topology protocols with the redundant multiple traffic service paths of OpMiGua. We analyse the problems and limitations imposed on the network architecture and propose our topology solution called the SM chain-connectivity. The analysis and the proposed schemes are verified based on results obtained from simulations. Furthermore, we design an integrated logical OpMiGua node that relies on an Ethernet switch instead of the Optical Packet Switch for the Statistically Multiplexed traffic. To date, to our knowledge there are no studies analysing the compatibility of Ethernet and its protection mechanisms in a hybrid optical network. This is the first work addressing the use of Ethernet in OpMiGua.

Cloud computing has gained remarkable popularity in the recent years by a wide spectrum of consumers, ranging from small start-ups to governments. However, its benefits in terms of flexibility, scalability, and low upfront investments, are shadowed by security challenges which inhibit its adoption. In particular, these highly flexible but complex cloud computing environments are prone to misconfigurations leading to security incidents, eg, erroneous exposure of services due to faulty network security configurations. In this thesis we present a novel approach in the security assessment of multi-tier architectures deployed on infrastructure clouds such as Amazon EC2. In order to perform this assessment for the currently deployed configuration, we automated the process of extracting the configuration using the Amazon API and translating it into a generic data model for later analysis. In the assessment we focused on the reachability and vulnerability of services in the virtual infrastructure, and presented a way for the visualization andautomated analysis based on reachability and attack graphs. We proposed a query and policy language for the analysis which can be used to obtain insights into the configuration and to specify desired and undesired configurations. We have implemented the security assessment in a prototype and evaluated it for practical andtheoretical scenarios. Furthermore, a framework is presented which allows the evaluation of configuration changes in the agile and dynamic cloud environments with regard to properties like vulnerabilities or expected availability. In case of a vulnerability perspective, this evaluation can be used to monitor the securitylevels of the configuration over its lifetime and to indicate degradations.

Nowadays, verification of programs is gaining increased importance. The software industry appears more and more interested in methods and tools to ensure security in their applications. Java Modeling Language has been successfully used in the past by programmers to express their intentions in the Design by Contract fashion in sequential programming. One of the design goals of JML was to improve the functional software correctness of Java applications. Regarding the verification of security properties, JML was mostly successful in Java Smart Card applets due to the specifics of these applications. In this thesis work we investigate the feasibility of JML to express high-level security properties in Java applications that have more realistic requirements and are implemented in the object oriented technology. We do a threat analysis of a case study regarding a medical clinic and derive the required security properties to secure the application. We develop a prototype application where we specify high-level security properties with JML and use a runtime assertion checking tool to verify the code. We model the functional behavior of the prototype that establishes the security proper-ties as a finite state automaton. Our prototype is developed based on this automaton. States and state transitions modeled in the automaton are expressed in the prototype with JML annotations and verified during runtime. We observe that currently available features in JML are not very feasible to capture the security related behavior of Java programs on the level of the entire application.

In today's business Information technology (IT) and Information plays a key role. Due todevelopment and influence of Information Technology, using systems, IT services andnetworks cannot be avoided in the business and they all need to be protected and secured.In order to ensure such a higher sort of security and protection, the Information securitysystem (ISS) have been used. Still the businesses today are enveloped with higher risks andupshots which are also being narrower and keeping changed consistently. At suchcircumstance the solution providing method should be very unique and narrower to each andevery slot of business, for a competitive and higher security. Thus such compact solutionsbeen given by Business Continuity Planning (BCP) method. Business Continuity Plan, a chiefidea engendered from the stream of information security.This research involves with a case study in regard to the Railway sector in making a BusinessContinuity Planning (BCP) on Network security, System Security and Physical Security of it.Thus the way of presentation been more systematically followed up in order to make thereader to understand the results more easily.Following in the Chapter 1 and Chapter 2, the Introduction and background studies which areneeded to be known to draw a BCP plan on Network, System and Physical Securities. Chapter3 Result section, will gives the recommendation that need to be followed for drawing aNetwork, System and Physical Securities in a railway network. / Done in Southern Indian Railways, India.

Owing to the fast progress of mobile communication technologies and the ubiquity of mobile networks, users can communicate with each other anytime and anywhere as long as they carry their smart and tiny mobile phones. This convenient communication service is quite popular and gradually joins in the people¡¦s life. Nevertheless, lots of attacks, such as the men-in-the-middle attacks and the replay attacks, are seriously threatening the security of the mobile networks and affecting the quality of the service simultaneously. Many security mechanisms for mobile communication have been introduced in the literature. Among these mechanisms, authentication plays a very important role in the entire mobile network system and acts as the first defense against the attackers since it can ensure the correctness of the identities of communication entities before they engage in any other communication activities. Therefore, to guarantee the quality of this advanced service, an efficient (especially, user efficient) and secure authentication scheme is urgently desired. In this thesis, we will propose a robust authentication scheme for mobile communication systems. Not only does the proposed scheme achieve mutual authentication, but also it greatly reduces the computation and communication cost of mobile users as compared with the existing authentication schemes.

Due to the growing interest in electronic commerce, more and more transactions now happen online. Thus, fair transactions between customers and merchants are getting important. To gain the fairness of the exchange of digital items, fair exchange protocols have been proposed and well studied. Most of the traditional fair exchange protocols are concerned about the exchange of digital items, such as digital signatures, contracts, and documents. Recently, researchers pay attention to the exchange of digital goods along with electronic cash, and have proposed some fair transaction protocols based on electronic cash. To buy digital contents via electronic cash through network, the anonymity property as traditional cash possesses must be guaranteed. It means that the payment information of the customer cannot be revealed to anyone else including the trusted third party (TTP) who helps the customer and the merchant with resolving possible disputes in the protocol. Since the customer and the merchant may not trust each other in an electronic transaction. In a fair exchange protocol, a TTP is employed to achieve true fairness. An on-line TTP has to take part in all transactions while they are proceeding. Despite it can gain true fairness, it is inefficient due to on-line interaction with the TTP. On the other hand, an off-line TTP does not need to join in the transaction protocol in normal cases. Instead, it participates in the protocol only when disputes happen. It is efficient and fair, and more feasible in practical situations. In this thesis, we propose a fair transaction protocol based on electronic cash. With the extended research on electronic cash, we have designed a fair transaction protocol that is suitable for any electronic cash system. By using an off-line TTP, the protocol is more efficient and practical. Furthermore, payment information of the customer cannot be known to anyone else including the TTP, and thus, the anonymity of the customer is protected completely in our protocol.

The technology of electronic cash makes it possible to transmit digital money over communication networks during electronic transactions. Owing to the untraceability and unforgeability properties, electronic cash can protect the privacy of customers and guarantee the security of payments in the transactions. This manuscript introduces an efficient electronic cash protocol where it only requires minimal storage for each customer to withdraw w dollars from the bank and spend the w dollars in a sequence of transactions. Compared with traditional electronic cash protocols, the proposed method greatly reduces not only the storage required for the customers but the communication traffic in the transactions as well. Furthermore, the computation cost of the entire protocol is lower than the traditional ones and it also achieves the customer efficiency property. It turns out that the proposed protocol is much more suitable for the storage-limited or hardware-limited environments, such as smart card computing or mobile commerce, than the traditional electronic cash protocols in a sequence of payments. In addition, we examine the security of the proposed electronic cash protocol from the customer¡¦s, the shop¡¦s, and the bank¡¦s points of view, respectively. Since the proposed protocol is based on a generic partially blind signature scheme, it can be implemented by any partially blind signature scheme as long as it is secure and user efficient.

Due to convenience and efficiency, electronic voting (e-voting) techniques gradually replace traditional paper-based voting activities in some developed countries. A secure anonymous e-voting system has to satisfy many properties, such as completeness, tally correctness, and uncoercibility, where the uncoercibility property is the most difficult one to be achieved. Since each voter can obtain a voting receipt in an electronic voting system, coercion and bribe (vote-buying and vote-selling are included) become more and more serious in electronic voting environments than traditional paper-based voting environments. Unfortunately, most of the solutions, like receipt-freeness or untappable channels, proposed in the literature, are impractical owing to lack of efficiency or too complicated to be implemented. It will make uncoercible e-voting systems unacceptable by the people. In order to cope with the drawbacks of the previous schemes, this thesis will present a generic idea, which is independent of the underlying cryptographic components, on electronic voting to achieve the uncoercibility property and other requirements. The proposed method is an efficient and quite practical solution to match the current environments of electronic voting.

In manufacturing industrial, for example, petrochemical plant, the promotion of technology makes manufacturing process computerization to be possible. The systems which control the manufacturing process are called Process Control System. Enterprises introduce the projects of process improvement to reduce the operation cost and enhance the product quality. It is necessary to have comprehensive information and technology to support the success of project for process improvement. Thus, it is a trend to setup the connections among Process Control Network, Process Information Network and Intranet. Due to the connections among networks, Process Control System is facing the threats of computer viruses, worms, attackers, and other malicious codes. Process Control System controls the manufacturing process base on the instructions issued from operators to maintain plant operations in a safe condition. Process Control System is the kernel of process operations. If Process Control System is being attacked or infected by computer viruses, the impacts would be the disclosure of critical business information, the failure of servers/workstations for monitoring process, or Process Control System fails totally that result in the plant operations with risky. The worst case would be an incident about pollution of environment, explosion, properties destroyed, or life lost. Therefore, enterprise should focus on reinforcing the information security mechanism of Process Control System to ensure plant operations reliably and safely. The objectives of this study are: a) To realize the challenges and threats that Process Control System is facing by the way of literature review. b) To discuss information security management related issues and resolutions of Process Control System base on physical, network, and servers respectively. c) To discuss the efficiency of the model of information security management that has been implemented in the enterprise. d) To make this study as a reference for related industries.