Safeguarding health data with enhanced accountability and patient awareness

Several factors are driving the transition from paper-based health records to electronic health record systems. In the United States, the adoption rate of electronic health record systems significantly increased after "Meaningful Use" incentive program was started in 2009. While increased use of electronic health record systems could improve the efficiency and quality of healthcare services, it can also lead to a number of security and privacy issues, such as identity theft and healthcare fraud. Such incidents could have negative impact on trustworthiness of electronic health record technology itself and thereby could limit its benefits. In this dissertation, we tackle three challenges that we believe are important to improve the security and privacy in electronic health record systems. Our approach is based on an analysis of real-world incidents, namely theft and misuse of patient identity, unauthorized usage and update of electronic health records, and threats from insiders in healthcare organizations. Our contributions include design and development of a user-centric monitoring agent system that works on behalf of a patient (i.e., an end user) and securely monitors usage of the patient's identity credentials as well as access to her electronic health records. Such a monitoring agent can enhance patient's awareness and control and improve accountability for health records even in a distributed, multi-domain environment, which is typical in an e-healthcare setting. This will reduce the risk and loss caused by misuse of stolen data. In addition to the solution from a patient's perspective, we also propose a secure system architecture that can be used in healthcare organizations to enable robust auditing and management over client devices. This helps us further enhance patients' confidence in secure use of their health data.PhDCommittee Chair: Mustaque Ahamad; Committee Member: Douglas M. Blough; Committee Member: Ling Liu; Committee Member: Mark Braunstein; Committee Member: Wenke Le

Guess my vote : a study of opacity and information flow in voting systems

With an overall theme of information flow, this thesis has two main strands. In the first part of the thesis, I review existing information flow properties, highlighting a recent definition known as opacity [25]. Intuitively, a predicate cP is opaque if for every run in which cP is true, there exists an indistinguishable run in which it is false, where a run can be regarded as a sequence of events. Hence, the observer is never able to establish the truth of cPo The predicate cP can be defined according to requirements of the system, giving opacity a great deal of flexibility and versatility. Opacity is then studied in relation to several well-known definitions for information flow. As will be shown, several of these properties can be cast as variations of opacity, while others have a relationship by implication with the opacity property [139]. This demonstrates the flexibility of opacity, at the same time establishing its distinct character. In the second part of the thesis, I investigate information flow in voting systems. Pret a Voter [36] is the main exemplar, and is compared to other schemes in the case study. I first analyse information flow in Pret a Voter and the FOO scheme [59], concentrating on the core protocols. The aim is to investigate the security requirements of each scheme, and the extent to which they can be captured using opacity. I then discuss a systems-based analysis of Pret a Voter [163], which adapts and extends an earlier analysis of the Chaum [35] and Neff [131]' [132]' [133] schemes in [92]. Although this analysis has identified several potential vulnerabilities, it cannot be regarded as systematic, and a more rigorous approach may be necessary. It is possible that a combination of the information flow and systems- based analyses might be the answer. The analysis of coercion-resistance, which is performed on Pret a Voter and the FOO scheme, may exemplify this more systematic approach. Receipt-freeness usually means that the voter is unable to construct a proof of her vote. Coercion-resistance is a stronger property in that it accounts for the possibility of interaction between the coercer and the voter during protocol execution. It appears that the opacity property is ideally suited to expressing the requirements for coercion-resistance in each scheme. A formal definition of receipt-freeness cast as a variation of opacity is proposed [138], together with suggestions on how it might be reinforced to capture coercion-resistance. In total, the thesis demonstrates the remarkable flexibility of opacity, both in expressing differing security requirements and as a tool for security analysis. This work lays the groundwork for future enhancement of the opacity framework.EThOS - Electronic Theses Online ServiceDSTL : EPSRCGBUnited Kingdo

CardS4: modal theorem proving on Java smart cards, Journal of Telecommunications and Information Technology, 2002, nr 4

We describe a successful implementation of a theorem prover for modal logic S4 that runs on a Java smart card with only 512 KBytes of RAM and 32 KBytes of EEPROM. Since proof search in S4 can lead to infinite branches, this is “proof of principle” that non-trivial modal deduction is feasible even on current Java cards. We hope to use this prover as the basis of an on-board security manager for restricting the flow of “secrets” between multiple applets residing on the same card, although much work needs to be done to design the appropriate modal logics of “permission” and “obligations”. Such security concerns are the major impediments to the commercial deployment of multi-application smart cards

Journal of Telecommunications and Information Technology, 2002, nr 4

kwartalni

The use of data-mining for the automatic formation of tactics

This paper discusses the usse of data-mining for the automatic formation of tactics. It was presented at the Workshop on Computer-Supported Mathematical Theory Development held at IJCAR in 2004. The aim of this project is to evaluate the applicability of data-mining techniques to the automatic formation of tactics from large corpuses of proofs. We data-mine information from large proof corpuses to find commonly occurring patterns. These patterns are then evolved into tactics using genetic programming techniques

Cloudarmor: Supporting Reputation-Based Trust Management for Cloud Services

Cloud services have become predominant in the current technological era. For the rich set of features provided by cloud services, consumers want to access the services while protecting their privacy. In this kind of environment, protection of cloud services will become a significant problem. So, research has started for a system, which lets the users access cloud services without losing the privacy of their data. Trust management and identity model makes sense in this case. The identity model maintains the authentication and authorization of the components involved in the system and trust-based model provides us with a dynamic way of identifying issues and attacks with the system and take appropriate actions. Further, a trust management-based system provides us with a new set of challenges such as reputation-based attacks, availability of components, and misleading trust feedbacks. Collusion attacks and Sybil attacks form a significant part of these challenges. This paper aims to solve the above problems in a trust management-based model by introducing a credibility model on top of a new trust management model, which addresses these use-cases, and also provides reliability and availability

Efficient cryptographic primitives: Secure comparison, binary decomposition and proxy re-encryption

”Data outsourcing becomes an essential paradigm for an organization to reduce operation costs on supporting and managing its IT infrastructure. When sensitive data are outsourced to a remote server, the data generally need to be encrypted before outsourcing. To preserve the confidentiality of the data, any computations performed by the server should only be on the encrypted data. In other words, the encrypted data should not be decrypted during any stage of the computation. This kind of task is commonly termed as query processing over encrypted data (QPED). One natural solution to solve the QPED problem is to utilize fully homomorphic encryption. However, fully homomorphic encryption is yet to be practical. The second solution is to adopt multi-server setting. However, the existing work is not efficient. Their implementations adopt costly primitives, such as secure comparison, binary decomposition among others, which reduce the efficiency of the whole protocols. Therefore, the improvement of these primitives results in high efficiency of the protocols. To have a well-defined scope, the following types of computations are considered: secure comparison (CMP), secure binary decomposition (SBD) and proxy re-encryption (PRE). We adopt the secret sharing scheme and paillier public key encryption as building blocks, and all computations can be done on the encrypted data by utilizing multiple servers. We analyze the security and the complexity of our proposed protocols, and their efficiencies are evaluated by comparing with the existing solutions.”--Abstract, page iii

Implementation-level analysis of cryptographic protocols and their applications to e-voting systems

Formal verification of security properties of both cryptographic operations, such as encryption, and protocols based on them, such as TLS, has been the goal of a substantial research effort in the last three decades. One fundamental limitation in the verification of these security properties is that analyses are typically carried out at the design level and hence they do not provide reliable guarantees on the implementations of these operations/protocols. To overcome this limitation, in this thesis we aim at establishing formally justified cryptographic guarantees directly at the implementation level for systems that are coded in Java and use cryptography. Our approach is based on a general framework for the cryptographic verification of Java programs (the CVJ framework) which formally links cryptographic indistinguishability properties and noninterference properties. In this way, it enables existing tools that can check standard noninterference properties, but a priori cannot deal with cryptography, to also establish cryptographic privacy properties for Java systems. The CVJ framework is stated and proven for a Java-like formal language which however does not cover all the data types and features commonly used in Java programs. Moreover, the framework originally supports only one cryptographic operation, namely public-key encryption. The first contribution of this thesis is hence to extend and to instantiate the CVJ framework in order to make it more widely applicable. We extend the underlying formal language with some features of Java which have not been captured yet, such as concurrency, and we restate and prove all the results of the framework to carry them over into this extended language. We then further instantiate the framework with additional cryptographic operations: digital signatures and public-key encryption, both now also including a public-key infrastructure, (private) symmetric encryption, and nonce generation. The methods and techniques developed within the CVJ framework are relevant and applicable independently of any specific tool employed. However, to illustrate the usefulness of this approach, we apply the framework along with two verification tools for Java programs, namely the fully automated static checker Joana and the interactive theorem prover KeY, to establish strong cryptographic privacy properties for systems which use cryptography, such as client-server applications and e-voting systems. In this context, the second major contribution of this thesis is the design, the implementation, and the deployment of a novel remote voting system called sElect (secure/simple elections). sElect is designed to be particularly simple and lightweight in terms of its structure, the cryptography it uses, and the user experience. One of its unique features is a fully automated procedure which does not require any user interaction and it is triggered as soon as voters look at the election result, allowing them to verify that their vote has been properly counted. The component of sElect which provides vote privacy is implemented in Java such that we can establish cryptographic guarantees directly on its implementation: by combining the techniques of the CVJ framework with a hybrid approach for proving noninterference, we are able to show that the Java implementation ensures strong cryptographic privacy of the votes cast with our proposed voting system. sElect is therefore the first full-fledged e-voting system with strong cryptographic security guarantees not only at the design level, but also on its implementation