An Efficient ID-Based Message Recoverable Privacy-Preserving Auditing Scheme

One of the most important benefits of public cloud storage is outsourcing of management and maintenance with easy accessibility and retrievability over the internet. However, outsourcing data on the cloud brings new challenges such as integrity verification and privacy of data. More concretely, once the users outsource their data on the cloud they have no longer physical control over the data and this leads to the integrity protection issue. Hence, it is crucial to guarantee proof of data storage and integrity of the outsourced data. Several pairing-based au- diting solutions have been proposed utilizing the Boneh-Lynn-Shacham (BLS) short signatures. They basically provide a desirable and efficient property of non-repudiation protocols. In this work, we propose the first ID-based privacy-preserving public auditing scheme with message recov- erable signatures. Because of message recoverable auditing scheme, the message itself is implicitly included during the verification step that was not possible in previously proposed auditing schemes. Furthermore, we point out that the algorithm suites of existing schemes is either insecure or very inefficient due to the choice of the underlying bilinear map and its baseline parameter selections. We show that our scheme is more ef- ficient than the recently proposed auditing schemes based on BLS like short signatures

Public Auditing for Ensuring Cloud Data Storage Security With Zero Knowledge Privacy

In cloud storage service, clients upload their data together with authentication information to cloud storage server. To ensure the availability and integrity of clients\u27 stored data, cloud server(CS) must prove to a verifier that he is actually storing all of the client\u27s data unchanged. And, enabling public auditability for cloud storage is of critical importance to users with constrained computing resources, who can resort to a third party auditor (TPA) to check the integrity of outsourced data. However, most of the existing proofs of retrievability schemes or proof of data possession schemes do not consider data privacy problem. Zero knowledge privacy requires TPA or the adversary can not deduce any information of the file data from auditing system. In this paper, after giving a new construction of a recently proposed cryptographic primitive named aggregatable signature based broadcast (ASBB) encryption scheme, we present an efficient public auditing scheme with zero knowledge privacy. The new scheme is as efficient as the scheme presented by Shacham and Waters without considering privacy and is secure in the random oracle model

Frameup: An Incriminatory Attack on Storj: A Peer to Peer Blockchain Enabled Distributed Storage System

In this work we present a primary account of frameup, an incriminatory attack made possible because of existing implementations in distributed peer to peer storage. The frameup attack shows that an adversary has the ability to store unencrypted data on the hard drives of people renting out their hard drive space. This is important to forensic examiners as it opens the door for possibly framing an innocent victim. Our work employs Storj as an example technology, due to its popularity and market size. Storj is a blockchain enabled system that allows people to rent out their hard drive space to other users around the world by employing a cryptocurrency token that is used to pay for the services rendered. It uses blockchain features like a transaction ledger, public/private key encryption, and cryptographic hash functions – but this work is not centered around blockchain. Our work discusses two frameup attacks, a preliminary and an optimized attack, both of which take advantage of Storj\u27s implementation. Results illustrate that Storj allows a potential adversary to store incriminating unencrypted files, or parts of files that are viewable on people\u27s systems when renting out their unused hard drive space. We offer potential solutions to mitigate our discovered attacks, a developed tool to review if a person has been a victim of a frameup attack, and a mechanism for showing that the files were stored on a hard drive without the renter\u27s knowledge. Our hope is that this work will inspire future security and forensics research directions in the exploration of distributed peer to peer storage systems that embrace blockchain and cryptocurrency tokens

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

Public Evidence from Secret Ballots

Elections seem simple---aren't they just counting? But they have a unique, challenging combination of security and privacy requirements. The stakes are high; the context is adversarial; the electorate needs to be convinced that the results are correct; and the secrecy of the ballot must be ensured. And they have practical constraints: time is of the essence, and voting systems need to be affordable and maintainable, and usable by voters, election officials, and pollworkers. It is thus not surprising that voting is a rich research area spanning theory, applied cryptography, practical systems analysis, usable security, and statistics. Election integrity involves two key concepts: convincing evidence that outcomes are correct and privacy, which amounts to convincing assurance that there is no evidence about how any given person voted. These are obviously in tension. We examine how current systems walk this tightrope.Comment: To appear in E-Vote-Id '1

Security architecture for Fog-To-Cloud continuum system

Nowadays, by increasing the number of connected devices to Internet rapidly, cloud computing cannot handle the real-time processing. Therefore, fog computing was emerged for providing data processing, filtering, aggregating, storing, network, and computing closer to the users. Fog computing provides real-time processing with lower latency than cloud. However, fog computing did not come to compete with cloud, it comes to complete the cloud. Therefore, a hierarchical Fog-to-Cloud (F2C) continuum system was introduced. The F2C system brings the collaboration between distributed fogs and centralized cloud. In F2C systems, one of the main challenges is security. Traditional cloud as security provider is not suitable for the F2C system due to be a single-point-of-failure; and even the increasing number of devices at the edge of the network brings scalability issues. Furthermore, traditional cloud security cannot be applied to the fog devices due to their lower computational power than cloud. On the other hand, considering fog nodes as security providers for the edge of the network brings Quality of Service (QoS) issues due to huge fog device’s computational power consumption by security algorithms. There are some security solutions for fog computing but they are not considering the hierarchical fog to cloud characteristics that can cause a no-secure collaboration between fog and cloud. In this thesis, the security considerations, attacks, challenges, requirements, and existing solutions are deeply analyzed and reviewed. And finally, a decoupled security architecture is proposed to provide the demanded security in hierarchical and distributed fashion with less impact on the QoS.Hoy en día, al aumentar rápidamente el número de dispositivos conectados a Internet, el cloud computing no puede gestionar el procesamiento en tiempo real. Por lo tanto, la informática de niebla surgió para proporcionar procesamiento de datos, filtrado, agregación, almacenamiento, red y computación más cercana a los usuarios. La computación nebulizada proporciona procesamiento en tiempo real con menor latencia que la nube. Sin embargo, la informática de niebla no llegó a competir con la nube, sino que viene a completar la nube. Por lo tanto, se introdujo un sistema continuo jerárquico de niebla a nube (F2C). El sistema F2C aporta la colaboración entre las nieblas distribuidas y la nube centralizada. En los sistemas F2C, uno de los principales retos es la seguridad. La nube tradicional como proveedor de seguridad no es adecuada para el sistema F2C debido a que se trata de un único punto de fallo; e incluso el creciente número de dispositivos en el borde de la red trae consigo problemas de escalabilidad. Además, la seguridad tradicional de la nube no se puede aplicar a los dispositivos de niebla debido a su menor poder computacional que la nube. Por otro lado, considerar los nodos de niebla como proveedores de seguridad para el borde de la red trae problemas de Calidad de Servicio (QoS) debido al enorme consumo de energía computacional del dispositivo de niebla por parte de los algoritmos de seguridad. Existen algunas soluciones de seguridad para la informática de niebla, pero no están considerando las características de niebla a nube jerárquica que pueden causar una colaboración insegura entre niebla y nube. En esta tesis, las consideraciones de seguridad, los ataques, los desafíos, los requisitos y las soluciones existentes se analizan y revisan en profundidad. Y finalmente, se propone una arquitectura de seguridad desacoplada para proporcionar la seguridad exigida de forma jerárquica y distribuida con menor impacto en la QoS.Postprint (published version

Sdhcare: Secured Distributed Healthcare System

In the healthcare sector, the move towards Electronic Health Records (EHR) systems has been accelerating in parallel with the increased adoption of IoT and smart devices. This is driven by the anticipated advantages for patients and healthcare providers. The integration of EHR and IoT makes it highly heterogeneous in terms of devices, network standards, platforms, types of data, connectivity, etc. Additionally, it introduces security, patient and data privacy, and trust challenges. To address such challenges, this thesis proposes an architecture that combines biometric-based blockchain technology with the EHR system. More specifically, this thesis describes a mechanism that uses a patient’s fingerprint for recovery of patient’s access control on their EHRs securely without compromising their privacy and identity. A secure distributed healthcare system (SDHCARE) is proposed to uniquely identify patients, enable them to control access to, and ensure recoverable access to their EHRs that are exchanged and synchronized between distributed healthcare providers. The system takes into account the security and privacy requirements of Health Insurance Portability and Accountability Act (HIPAA) compliance, and it overcomes the challenges of using secret keys as a patient’s identity to control access to EHRs. The system used distributed architecture with two layers being local to each healthcare provider that is a member of SDHCARE, and two layers shared across all members of SDCHARE system. SDHCARE system was prototyped and implemented in order to validate its functional requirements, security requirements, and to evaluate its performance. The results indicated successful fulfillment of design requirements without significant overhead on the performance as required by healthcare environment

Hierarchical Integrated Signature and Encryption

In this work, we introduce the notion of hierarchical integrated signature and encryption (HISE), wherein a single public key is used for both signature and encryption, and one can derive a secret key used only for decryption from the signing key, which enables secure delegation of decryption capability. HISE enjoys the benefit of key reuse, and admits individual key escrow. We present two generic constructions of HISE. One is from (constrained) identity-based encryption. The other is from uniform one-way function, public-key encryption, and general-purpose public-coin zero-knowledge proof of knowledge. To further attain global key escrow, we take a little detour to revisit global escrow PKE, an object both of independent interest and with many applications. We formalize the syntax and security model of global escrow PKE, and provide two generic constructions. The first embodies a generic approach to compile any PKE into one with global escrow property. The second establishes a connection between three-party non-interactive key exchange and global escrow PKE. Combining the results developed above, we obtain HISE schemes that support both individual and global key escrow. We instantiate our generic constructions of (global escrow) HISE and implement all the resulting concrete schemes for 128-bit security. Our schemes have performance that is comparable to the best Cartesian product combined public-key scheme, and exhibit advantages in terms of richer functionality and public key reuse. As a byproduct, we obtain a new global escrow PKE scheme that is $12-30 \times$ faster than the best prior work, which might be of independent interest

SECURE MULTI-PARTY COMPUTATION: HOW TO SOLVE THE CONFLICT BETWEEN SECURITY & BUSINESS INTELLIGENCE

Abstract: This work defines the security intelligence of a system based on secure multi-party computation in terms of correctness, fairness, rationality, trust, honesty, transparency, accountability, reliability, consistency, confidentiality, data integrity, non-repudiation, authentication, authorization, correct identification, privacy, safety and audit. It defines the security intelligence of a system comprehensively with a novel concept of collective intelligence. The cryptographic notion of security is applied to assess, analyze and mitigate the risks of bio-terrorism today. The definition of bioterrorism has been changed in terms of information security. This work also tries to resolve the conflict between the security intelligence and business intelligence in the context of bio-terrorism and highlights the new cryptographic challenges. Keywords: Security intelligence, Threat analytics, Business intelligence, Cross border bio-terrorism, Secure multi-party computation, Applied cryptography