Survey of Homomorphic schemes

Homomorphic encryption is increasingly becoming popular among researchers due to its future promises.Homomorphic encryption is a solution that allows a third party to process data in encrypted form. The decryption keys need not be shared.This paper summarizes the concept of homomorphic encryption and the work has been done in this field

Privacy-Preserving Regular Expression Evaluation on Encrypted Data

Motivated by the need to outsource file storage to untrusted clouds while still permitting controlled use of that data by authorized third parties, in this dissertation we present a family of protocols by which a client can evaluate a regular expression on an encrypted file stored at a server (the cloud), once authorized to do so by the file owner. We present a protocol that provably protects the privacy of the regular expression and the file contents from a malicious server and the privacy of the file contents (except for the evaluation result) from an honest-but-curious client. We then extend this protocol in two primary directions. In one direction, we develop a strengthened protocol that enables the client to detect any misbehavior of the server; in particular, the client can verify that the result of its regular-expression evaluation is based on the authentic file stored there by the data owner, and in this sense the file and evaluation result are authenticated to the client. The second direction in which we extend our initial protocol is motivated by the vast adoption of resource-constrained mobile devices, and the fact that our protocols involve relatively intensive client-server interaction and computation on the searching client. We therefore investigate an alternative in which the client (e.g., via her mobile device) can submit her encrypted regular expression to a partially trusted proxy, which then interacts with the server hosting the encrypted data and reports the encrypted evaluation result to the client. Neither the search query nor the result is revealed to an honest-but-curious proxy or malicious server during the process. We demonstrate the practicality of the protocol by prototyping a system to perform regular-expression searches on encrypted emails and evaluate its performance using a real-world email dataset.Doctor of Philosoph

A security concept for distributed data processing systems

Today, the amount of raw data available is abundant. As only a small part of this data is in a form fit for further processing, there is many data left to analyze and process. At the same time, cloud services are ubiquitous and allow even small businesses to perform large tasks of distributed data processing without the significant costs required for a suitable computational infrastructure. However, as more and more users transfer their data into the cloud for processing and storage, concerns about data security arise. An extensive review of data security research in today's cloud solutions confirms these concerns to be justified. The existing strategies for securing one's data are not adequate for many use cases. Therefore, this work proposes a holistic security concept for distributed data processing in the cloud. For the purpose of providing security in heterogeneous cloud environments, it statically analyzes a data flow prior to execution and determines the optimal security measurements. Without imposing strict requirements on the cloud services involved, it can be deployed in a broad range of scenarios. The concept's generic design can be adopted by existing data rocessing tools. An exemplary implementation is provided for the mashup tool FlexMash. Requirements, such as data confidentiality, integrity, access control, and scalability were evaluated to be met.Die heutige Menge an vorhandenen Daten ist enorm. Viele davon müssen zunächst verarbeitet und analysiert werden, da nur ein geringer Teil dieser Daten für die weitere Verarbeitung geeignet ist. Cloud-basierte Dienste sind allgegenwärtig und erlauben es auch kleineren Unternehmen Datenverarbeitung durchzuführen, ohne die Kosten von notwendiger Infrastruktur tragen zu müssen. Mit einer zunehmenden Zahl an Nutzern von Clouds wachsen jedoch auch Bedenken der Sicherheit. Eine ausführliche Durchsicht der aktuellen Forschung zu diesem Thema bestätigt diese Bedenken und existierende Strategien zur Sicherung der eigenen Daten berücksichtigen viele Fälle nicht. Daher stellt diese Arbeit ein ganzheitliches Sicherheitskonzept für die verteilte Datenverarbeitung in der Cloud vor. Damit Sicherheit in heterogenen Cloudumgebungen gewährleistet werden kann, wird ein Datenfluss vor der Ausführung statisch analysiert und es werden die für diesen Fluss optimalen Sicherheitsmaßnahmen festgelegt. Das Konzept besitzt einen breiten Anwendungsbereich, da keine straffen Anforderungen an die genutzten Dienste gestellt werden. Das generische Design des Konzepts ermöglicht eine einfache Integration in bereits existierende Datenverarbeitungsanwendungen, wie beispielhaft an FlexMash gezeigt wird. Anforderungen, wie die Vertraulichkeit von Daten, deren Integrität, Zugriffskontrolle und Skalierbarkeit des Systems konnten erreicht werden

Secure data storage and retrieval in cloud computing

Nowadays cloud computing has been widely recognised as one of the most inuential information technologies because of its unprecedented advantages. In spite of its widely recognised social and economic benefits, in cloud computing customers lose the direct control of their data and completely rely on the cloud to manage their data and computation, which raises significant security and privacy concerns and is one of the major barriers to the adoption of public cloud by many organisations and individuals. Therefore, it is desirable to apply practical security approaches to address the security risks for the wide adoption of cloud computing

Efficient Oblivious Evaluation Protocol and Conditional Disclosure of Secrets for DFA

In oblivious finite automata evaluation, one party holds a private automaton, and the other party holds a private string of characters. The objective is to let the parties know whether the string is accepted by the automaton or not, while keeping their inputs secret. The applications include DNA searching, pattern matching, and more. Most of the previous works are based on asymmetric cryptographic primitives, such as homomorphic encryption and oblivious transfer. These primitives are significantly slower than symmetric ones. Moreover, some protocols also require several rounds of interaction. As our main contribution, we propose an oblivious finite automata evaluation protocol via conditional disclosure of secrets (CDS), using one (potentially malicious) outsourcing server. This results in a constant-round protocol, and no heavy asymmetric-key primitives are needed. Our protocol is based on a building block called an oblivious CDS scheme for deterministic finite automata\u27\u27 which we also propose in this paper. In addition, we propose a standard CDS scheme for deterministic finite automata as an independent interest

Secure data sharing in cloud computing: a comprehensive review

Cloud Computing is an emerging technology, which relies on sharing computing resources. Sharing of data in the group is not secure as the cloud provider cannot be trusted. The fundamental difficulties in distributed computing of cloud suppliers is Data Security, Sharing, Resource scheduling and Energy consumption. Key-Aggregate cryptosystem used to secure private/public data in the cloud. This key is consistent size aggregate for adaptable decisions of ciphertext in cloud storage. Virtual Machines (VMs) provisioning is effectively empowered the cloud suppliers to effectively use their accessible resources and get higher benefits. The most effective method to share information resources among the individuals from the group in distributed storage is secure, flexible and efficient. Any data stored in different cloud data centers are corrupted, recovery using regenerative coding. Security is provided many techniques like Forward security, backward security, Key-Aggregate cryptosystem, Encryption and Re-encryption etc. The energy is reduced using Energy-Efficient Virtual Machines Scheduling in Multi-Tenant Data Centers

A Novel Hybrid Security Framework (HSF) with Vshield Based Firewall to Secure Cloud Computing Environment

Cloud Computing is an emerging technology that provides an enormous amount of computing resources which includes networks, servers and storages which are accessed through the internet. In addition it allows useful provisioning of the resources based on the user’s demands. A crucial aspect of cloud computing infrastructure is to provide secure and reliable services.  The main challenge lies in the security issues is to reduce the impact of third party attacks in the cloud computing environment. Hence a novel Hybrid Security Framework(HSF) based on Reinforcement Learning (RL) Methodology with Vshield Firewall is proposed for securing the cloud environment.  The RL method is used for deep packet inspection and VShiled based firewall is established to deny the attacks which are malicious when authenticating the signature of incoming packets. The bipartite pattern matching approach is integrated with the RL method to verify the signatures for obtaining the decisions quickly.  The simulation results shows that the hybrid security framework is effective when compared with the existing methods by considering response time, resource utilization and denial of malicious attacks.  This indicates that our proposed framework achieves not only better security but also attains better efficiency in cloud computing environment

From security to assurance in the cloud: a survey

The cloud computing paradigm has become a mainstream solution for the deployment of business processes and applications. In the public cloud vision, infrastructure, platform, and software services are provisioned to tenants (i.e., customers and service providers) on a pay-as-you-go basis. Cloud tenants can use cloud resources at lower prices, and higher performance and flexibility, than traditional on-premises resources, without having to care about infrastructure management. Still, cloud tenants remain concerned with the cloud's level of service and the nonfunctional properties their applications can count on. In the last few years, the research community has been focusing on the nonfunctional aspects of the cloud paradigm, among which cloud security stands out. Several approaches to security have been described and summarized in general surveys on cloud security techniques. The survey in this article focuses on the interface between cloud security and cloud security assurance. First, we provide an overview of the state of the art on cloud security. Then, we introduce the notion of cloud security assurance and analyze its growing impact on cloud security approaches. Finally, we present some recommendations for the development of next-generation cloud security and assurance solutions