Achieving k-anonymity using full domain generalization

Preserving privacy while publishing data has emerged as key research area in data security and has become a primary issue in publishing person specific sensitive information. How to preserve one's privacy efficiently is a critical issue while publishing data. K-anonymity is a key technique for de-identifying the sensitive datasets. In our work, we have described a framework to implement most of the k-anonymity algorithms and also proposed a novel scheme that produces better results with real-world datasets. Additionally, we suggest a new approach that attains better results by applying a novel approach and exploiting various characteristic of our suggested framework. The proposed approach uses the concept of breadth- search algorithm to generalize the lattice in bottom-up manner. the proposed algorithm generates the paths using predictive tagging of the nodes in the lattice in vertically.the proposed algorithm has less execution time than other full domain generalization algorithms for k-anonymization

Towards privacy preserving cooperative cloud based intrusion detection systems

Les systèmes infonuagiques deviennent de plus en plus complexes, dynamiques et vulnérables aux attaques. Par conséquent, il est de plus en plus difficile pour qu'un seul système de détection d'intrusion (IDS) basé sur le cloud puisse repérer toutes les menaces, en raison des lacunes de connaissances sur les attaques et leurs conséquences. Les études récentes dans le domaine de la cybersécurité ont démontré qu'une coopération entre les IDS d'un nuage pouvait apporter une plus grande efficacité de détection dans des systèmes informatiques aussi complexes. Grâce à cette coopération, les IDS d'un nuage peuvent se connecter et partager leurs connaissances afin d'améliorer l'exactitude de la détection et obtenir des bénéfices communs. L'anonymat des données échangées par les IDS constitue un élément crucial de l'IDS coopérative. Un IDS malveillant pourrait obtenir des informations confidentielles d'autres IDS en faisant des conclusions à partir des données observées. Pour résoudre ce problème, nous proposons un nouveau système de protection de la vie privée pour les IDS en nuage. Plus particulièrement, nous concevons un système uniforme qui intègre des techniques de protection de la vie privée dans des IDS basés sur l'apprentissage automatique pour obtenir des IDS qui respectent les informations personnelles. Ainsi, l'IDS permet de cacher des informations possédant des données confidentielles et sensibles dans les données partagées tout en améliorant ou en conservant la précision de la détection. Nous avons mis en œuvre un système basé sur plusieurs techniques d'apprentissage automatique et de protection de la vie privée. Les résultats indiquent que les IDS qui ont été étudiés peuvent détecter les intrusions sans utiliser nécessairement les données initiales. Les résultats (c'est-à-dire qu'aucune diminution significative de la précision n'a été enregistrée) peuvent être obtenus en se servant des nouvelles données générées, analogues aux données de départ sur le plan sémantique, mais pas sur le plan synthétique.Cloud systems are becoming more sophisticated, dynamic, and vulnerable to attacks. Therefore, it's becoming increasingly difficult for a single cloud-based Intrusion Detection System (IDS) to detect all attacks, because of limited and incomplete knowledge about attacks and their implications. The recent works on cybersecurity have shown that a co-operation among cloud-based IDSs can bring higher detection accuracy in such complex computer systems. Through collaboration, cloud-based IDSs can consult and share knowledge with other IDSs to enhance detection accuracy and achieve mutual benefits. One fundamental barrier within cooperative IDS is the anonymity of the data the IDS exchanges. Malicious IDS can obtain sensitive information from other IDSs by inferring from the observed data. To address this problem, we propose a new framework for achieving a privacy-preserving cooperative cloud-based IDS. Specifically, we design a unified framework that integrates privacy-preserving techniques into machine learning-based IDSs to obtain privacy-aware cooperative IDS. Therefore, this allows IDS to hide private and sensitive information in the shared data while improving or maintaining detection accuracy. The proposed framework has been implemented by considering several machine learning and privacy-preserving techniques. The results suggest that the consulted IDSs can detect intrusions without the need to use the original data. The results (i.e., no records of significant degradation in accuracy) can be achieved using the newly generated data, similar to the original data semantically but not synthetically

Usability heuristics for fast crime data anonymization in resource-constrained contexts

This thesis considers the case of mobile crime-reporting systems that have emerged as an effective and efficient data collection method in low and middle-income countries. Analyzing the data, can be helpful in addressing crime. Since law enforcement agencies in resource-constrained context typically do not have the expertise to handle these tasks, a cost-effective strategy is to outsource the data analytics tasks to third-party service providers. However, because of the sensitivity of the data, it is expedient to consider the issue of privacy. More specifically, this thesis considers the issue of finding low-intensive computational solutions to protecting the data even from an "honest-but-curious" service provider, while at the same time generating datasets that can be queried efficiently and reliably. This thesis offers a three-pronged solution approach. Firstly, the creation of a mobile application to facilitate crime reporting in a usable, secure and privacy-preserving manner. The second step proposes a streaming data anonymization algorithm, which analyses reported data based on occurrence rate rather than at a preset time on a static repository. Finally, in the third step the concept of using privacy preferences in creating anonymized datasets was considered. By taking into account user preferences the efficiency of the anonymization process is improved upon, which is beneficial in enabling fast data anonymization. Results from the prototype implementation and usability tests indicate that having a usable and covet crime-reporting application encourages users to declare crime occurrences. Anonymizing streaming data contributes to faster crime resolution times, and user privacy preferences are helpful in relaxing privacy constraints, which makes for more usable data from the querying perspective. This research presents considerable evidence that the concept of a three-pronged solution to addressing the issue of anonymity during crime reporting in a resource-constrained environment is promising. This solution can further assist the law enforcement agencies to partner with third party in deriving useful crime pattern knowledge without infringing on users' privacy. In the future, this research can be extended to more than one low-income or middle-income countries

Privacy Preserving Sensitive Data Publishing using (k,n,m) Anonymity Approach

Open Science movement has enabled extensive knowledge sharing by making research publications, software, data and samples available to the society and researchers. The demand for data sharing is increasing day by day due to the tremendous knowledge hidden in the digital data that is generated by humans and machines. However, data cannot be published as such due to the information leaks that can occur by linking the published data with other publically available datasets or with the help of some background knowledge. Various anonymization techniques have been proposed by researchers for privacy preserving sensitive data publishing. This paper proposes a (k,n,m) anonymity approach for sensitive data publishing by making use of the traditional k-anonymity technique. The selection of quasi identifiers is automated in this approach using graph theoretic algorithms and is further enhanced by choosing similar quasi identifiers based on the derived and composite attributes. The usual method of choosing a single value of ‘k’ is modified in this technique by selecting different values of ‘k’ for the same dataset based on the risk of exposure and sensitivity rank of the sensitive attributes. The proposed anonymity approach can be used for sensitive big data publishing after applying few extension mechanisms. Experimental results show that the proposed technique is practical and can be implemented efficiently on a plethora of datasets

A Hybrid Multi-user Cloud Access Control based Block Chain Framework for Privacy Preserving Distributed Databases

Most of the traditional medical applications are insecure and difficult to compute the data integrity with variable hash size. Traditional medical data security systems are insecure and it depend on static parameters for data security. Also, distributed based cloud storage systems are independent of integrity computational and data security due to unstructured data and computational memory. As the size of the data and its dimensions are increasing in the public and private cloud servers, it is difficult to provide the machine learning based privacy preserving in cloud computing environment. Block-chain technology plays a vital role for large cloud databases. Most of the conventional block-chain frameworks are based on the existing integrity and confidentiality models. Also, these models are based on the data size and file format. In this model, a novel integrity verification and encryption framework is designed and implemented in cloud environment.  In order to overcome these problems in the cloud computing environment, a hybrid integrity and security-based block-chain framework is designed and implemented on the large distributed databases. In this framework,a novel decision tree classifier is used along with non-linear mathematical hash algorithm and advanced attribute-based encryption models are used to improve the privacy of multiple users on the large cloud datasets. Experimental results proved that the proposed advanced privacy preserving based block-chain technology has better efficiency than the traditional block-chain based privacy preserving systems on large distributed databases

Location Privacy in the Era of Big Data and Machine Learning

Location data of individuals is one of the most sensitive sources of information that once revealed to ill-intended individuals or service providers, can cause severe privacy concerns. In this thesis, we aim at preserving the privacy of users in telecommunication networks against untrusted service providers as well as improving their privacy in the publication of location datasets. For improving the location privacy of users in telecommunication networks, we consider the movement of users in trajectories and investigate the threats that the query history may pose on location privacy. We develop an attack model based on the Viterbi algorithm termed as Viterbi attack, which represents a realistic privacy threat in trajectories. Next, we propose a metric called transition entropy that helps to evaluate the performance of dummy generation algorithms, followed by developing a robust dummy generation algorithm that can defend users against the Viterbi attack. We compare and evaluate our proposed algorithm and metric on a publicly available dataset published by Microsoft, i.e., Geolife dataset. For privacy preserving data publishing, an enhanced framework for anonymization of spatio-temporal trajectory datasets termed the machine learning based anonymization (MLA) is proposed. The framework consists of a robust alignment technique and a machine learning approach for clustering datasets. The framework and all the proposed algorithms are applied to the Geolife dataset, which includes GPS logs of over 180 users in Beijing, China