Anonymous Access Research Articles

Provable Security for the Onion Routing and Mix Network Packet Format Sphinx

Onion routing and mix networks are fundamental concepts to provide users with anonymous access to the Internet. Various corresponding solutions rely on the Sphinx packet format. However, flaws in Sphinx's underlying proof strategy were found recently. It is thus currently unclear which guarantees Sphinx actually provides, and, even worse, there is no suitable proof strategy available. In this paper, we restore the security foundation for all these works by building an analytical framework for Sphinx. We discover that the previously-used Decisional Diffie-Hellman (DDH) assumption is insufficient for a security proof and show that the Gap Diffie-Hellman (GDH) assumption is required instead. We apply it to prove that a slightly adapted version of the Sphinx packet format is secure under the GDH assumption. We are thus, to the best of our knowledge, the first to provide a detailed, in-depth security proof for Sphinx that holds. Our adaptations to Sphinx are necessary, as we demonstrate with an attack on sender privacy that would otherwise be possible in Sphinx's adversary model.

Anonymous Access System with Limited Number of Uses in a Trustless Environment

This article proposes a novel method for managing usage counters within an anonymous credential system, addressing the limitation of traditional anonymous credentials in tracking repeated use. The method takes advantage of blockchain technology through Smart Contracts deployed on the Ethereum network to enforce a predetermined maximum number of uses for a given credential. Users retain control over increments by providing zero-knowledge proofs (ZKPs) demonstrating private key possession and agreement on the increment value. This approach prevents replay attacks and ensures transparency and security. A prototype implementation on a private Ethereum blockchain demonstrates the feasibility and efficiency of the proposed method, paving the way for its potential deployment in real-world applications requiring both anonymity and usage tracking.

To Study the Use of Entropy and the Preprocessing Step in Analyzing Web Users' Behavior and Improving Web Mining

The study of entropy's application to online use mining is the main goal of the work. By using the Reference Length approach, entropy provides an additional option for figuring out the ratio of auxiliary pages in the session identification. Two distinct online portals were used for the experiment. The first log file was downloaded via the web portal of a virtual learning environment course. The online gateway with anonymous access provided the second log file. When entropy and sitemap estimations of the ratio of auxiliary pages were compared, it was discovered that entropy could replace the sitemap estimate of the ratio of auxiliary pages with a full-valued substitute in the situation of sitemap abundance.

Towards accountable and privacy-preserving blockchain-based access control for data sharing

The integration of blockchain technology with Access Control (AC) systems presents novel opportunities for enhancing data security within decentralized architectures, which is drawing increasing attention in Data Sharing (DS) applications. However, existing works reveal a gap in achieving accountability for anonymous access in the absence of a centralized trusted authority. To address this issue, this paper introduces InvisiReveal, a novel Blockchain-Based AC (BBAC) framework that achieves permission invisibility, access anonymity, and accountability without extra trust assumptions. Users in InvisiReveal generate anonymous credentials to authenticate their requests using Zero Knowledge Proof. To enable accountability, a novel blockchain-oriented verifiable commitment (BC-VC) protocol is designed that allows a user to commit a confidential traceable tag to the blockchain. The system could unveil a malicious requester’s identity by opening the tag commitment under collaboration with the victim user and blockchain. We implement a prototype of InvisiReveal to evaluate its practicality, where an access request is verified within 5 ms.

ABAC-PA2: Attribute-Based Access Control Model with Privacy aware Anonymous Access

Cloud computing offers an excellent platform for sharing information and services among departments, partners, customers, and other parties. To ensure the effectiveness of a cloud deployment, it is imperative that resources and data are available in a secure and efficient manner. The protection of personally identifiable information (PII) is a critical requirement for many organizations in order to prevent unauthorized disclosure of that information. In spite of the fact that private information may not be stored within an authorized organization, it can still be protected. It has been shown in recent literature that anonymity can be used to preserve PII privacy. The current methodology for anonymous access is based on certificates rather than subject identity or attribute-based encryption. Identity-based access control is inflexible and violates privacy laws. Access to a certificate can be linked using a certificate that poses a risk of re-identification. The types of objects that can be encrypted by attributes are limited.To preserve the privacy of attributes set of subject and object, we extend the attribute-based access control (ABAC) model by expressing privacy requirements with anonymous access. It inherits several characteristics from ABAC, including fine-grained authorizations, unlimited object types, policy flexibility, and object privacy. ABAC-PA2 uses homomorphic attribute-based signature (HABS), a secure anonymous access framework that enhances ABAC's identity-less and incorporates privacy-preserving principles by assigning privacy levels to resources.

PriGenX: Privacy-Preserving Query With Anonymous Access Control for Genomic Data

Presently, similar sequence search is a fundamental technique in genomic data research. Patients or researchers, who want to check whether they or their research objects have genetic diseases or potential illnesses, need to query similar sequences with their genes in certain genomic databases. As a consequence, this may raise privacy issues since the genomic data are regarded as an identifier of each individual and contain lots of sensitive information. Up to date, some solutions have been brought up for achieving secure similarity search over genomic data, but they are still defective in searching exact similar sequences, supporting fine-grained access control, preventing side information leakage, and being built on strong security models at the same time. In this paper, aiming at the above challenge, we propose a maliciously secure similar sequence search scheme with fine-grained access control over genomic data, named PriGenX. Based on oblivious transfer and authenticated garbling techniques, our scheme also supports secure access control with anonymity for protecting the identity of each party preventing side information leakage, and implementing a flexible over-threshold similarity search. Experimental results and security analysis indicate that our scheme is scalable and maliciously secure.

Anonymity in Attribute-Based Access Control: Framework and Metric

Anonymous access is an effective method for preserving privacy in access control. This study assumes that anonymous access control requires both frameworks and policies. Numerous solutions have been proposed for anonymous access at the framework level. In this study, these solutions are analyzed and quantified using a unified attribute-based access control (ABAC) anonymous access reference framework. Anonymous access at the framework level is the first line of defense, and inappropriate policies may undermine subject anonymity. An anonymity metric is proposed at the policy level to prevent authorization authority from re-identification using specific attributes and policies. The anonymity metric evaluates the risk of re-identifying a subject due to inappropriate access requests, as well as subject attribute assignment schemes and policies. This study is the first to focus on anonymity at the policy level in ABAC. Furthermore, a formal definition of anonymity suitable for ABAC is proposed. The feasibility of the proposed anonymity metric is verified through simulations.

Newer Challenges in Sexual Health

More and more professionals in the field of Sexual Health are encountering problems that do not find a mention in conventional diagnostic manuals. Sexless marriages are one such problem. Its reported incidence varies from 2% to 45% in the age group 18–60 years, depending on the definition used. The figures are higher for the ages of 60 or more. The reasons for the same range from economic development and its ramifications, the monotony of sexual experience, the emergence of the smartphone, and social networking sites, to a possible role of substance use. Artificial intelligence could offer a solution to this vexed problem, although the benefits of anonymous access and a non-judgmental format could actually contribute to increasing the problem.

On-Demand Anonymous Access and Roaming Authentication Protocols for 6G Satellite-Ground Integrated Networks.

Satellite-ground integrated networks (SGIN) are in line with 6th generation wireless network technology (6G) requirements. However, security and privacy issues are challenging with heterogeneous networks. Specifically, although 5G authentication and key agreement (AKA) protects terminal anonymity, privacy preserving authentication protocols are still important in satellite networks. Meanwhile, 6G will have a large number of nodes with low energy consumption. The balance between security and performance needs to be investigated. Furthermore, 6G networks will likely belong to different operators. How to optimize the repeated authentication during roaming between different networks is also a key issue. To address these challenges, on-demand anonymous access and novel roaming authentication protocols are presented in this paper. Ordinary nodes implement unlinkable authentication by adopting a bilinear pairing-based short group signature algorithm. When low-energy nodes achieve fast authentication by utilizing the proposed lightweight batch authentication protocol, which can protect malicious nodes from DoS attacks. An efficient cross-domain roaming authentication protocol, which allows terminals to quickly connect to different operator networks, is designed to reduce the authentication delay. The security of our scheme is verified through formal and informal security analysis. Finally, the performance analysis results show that our scheme is feasible.

How to Grant Anonymous Access

In this paper, we propose three protocols to share, among a set of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> competing entities, the responsibility to grant anonymous access to a resource. The protocols we propose vary in their settings to take into account central or distributed registration. We prove that any subset of guardian authorities can neither tamper with, nor forge, new access-key tokens. Besides, two of the methods we propose are resistant to the eventual appearance of quantum computers. The protocols we propose permit new approaches for cryptographic applications such as electronic voting or blockchain access.

Factors Influencing the Acceptability of Nominal, Non-nominal, and Anonymous HIV Testing Options Among Young Men Living in Vancouver, Canada: A Qualitative Study.

Individuals unaware of their HIV seropositive status continue to represent a key "driver" of the HIV epidemic. Strategies to improve initiation into the HIV treatment cascade, including among young men, are required. This study assesses the acceptability of three HIV testing options among young cisgender men living in Vancouver, British Columbia. Using a modified grounded theory approach, we conducted semi-structured interviews with 45 young cisgender men ages 18-30 years to identify the factors influencing the acceptability of diverse HIV testing approaches. Participants ascribed value to non-nominal testing as a means of providing a secure pathway to HIV-related care for those who test positive while also safeguarding privacy. Anonymous HIV testing was problematized by participants as potentially creating difficulty in accessing ongoing HIV-related care. Most participants preferred non-nominal testing. Nevertheless, based on principles of equity, we argue that anonymous access to one's serostatus should be available, especially within a criminalized context.

Energy-Efficient Edge Optimization Embedded System Using Graph Theory with 2-Tiered Security

The development of the Internet of Things (IoT) network has greatly benefited from the expansion of sensing technologies. These networks interconnect with wireless systems and collaborate with other devices using multi-hop communication. Besides data sensing, these devices also perform other operations such as compression, aggregation, and transmission. Recently, many solutions have been proposed to overcome the various research challenges of wireless sensor networks; however, energy efficiency with optimized intelligence is still a burning research problem that needs to be tackled. Thus, this paper presents an energy-efficient enabled edge optimization embedded system using graph theory for increasing performance in terms of network lifetime and scalability. First, minimum spanning trees are extracted using artificial intelligence techniques to improve the embedded system for response time and latency performance. Second, the extracted routes are provided with full protection against anonymous access in a two-tiered system. Third, the IoT systems collaborate with mobile sinks, and they need to be authenticated using lightweight techniques for the involvement in routing sensed information. Moreover, edge networks further provide the timely delivery of data to mobile sinks with less overhead on IoT devices. Finally, the proposed system is verified using simulations, revealing its significance to existing approaches.

Time-series analysis of presentations to four syringe dispensing machines and a needle and syringe programme during COVID-19 lockdowns in Melbourne, Australia

BackgroundAustralian harm reduction services are provided via a mix of modalities, including fixed-site needle and syringe programmes (NSP) and syringe-dispensing machines (SDMs). SDMs are cost-effective and provide 24-h anonymous access to needles/syringes, often to underserved geographic areas, and can attract clientele who may choose not to use NSPs. The introduction of COVID-19 control measures saw disruptions and adaptations to the provision of harm reduction services. It is possible that SDMs filled the gap in otherwise disrupted harm reduction services in Melbourne. In this paper, we use data from four SDMs and an NSP to explore changes to harm reduction usage during periods of COVID-19 lockdowns in Melbourne, Australia, in 2020.MethodsOur data span September 2017–December 2020. We analysed daily counts of SDM use and monthly counts of NSP use, according to unique presentations to both. Auto-regressive integrated moving average (ARIMA) time-series models were fitted to the data with the effects of lockdowns estimated via a step function.ResultsAcross the study period, we estimated 85,851 SDM presentations and 29,051 NSP presentations. Usage across both the SDMs and the NSP declined during the COVID-19 lockdowns, but only the decline in SDM usage was significant in ARIMA analysis.ConclusionsThe slight, but significant decline in SDM use suggests barriers to access, though this may have been mitigated by SDM users acquiring needles/syringes from other sources. The decline, however, may be a concern if it led to lowered needle/syringe coverage and a subsequent increase in injecting risk. Further work is needed to properly explore potential changes in preference for needle/syringe acquisition site and associated barriers. Importantly, this work adds to the body of literature around the impacts of COVID-19 on harm reduction provision and potential areas of improvement.

Blockchain-Enabled Tripartite Anonymous Identification Trusted Service Provisioning in Industrial IoT

The integration of Internet of Things (IoT) and industry reveals the industrial manufacturing developments, resulting in Industry IoT (IIoT), which is to provide a general interconnect system for the access of various industry devices. However, as the amount and type of terminal increase, the creditability and privacy protection of terminal devices are hard to be guaranteed in IIoT, since the data and digital identity of access devices are nearly transparent for more devices in networks. It is a critical issue for the security of IIoT whether the access and service of device are trustworthy. In this article, we present a novel private blockchain-enabled trusted anonymous access (BlockTrust) architecture for IIoT, where the distributed cloud radio and optical access networks (C-RONs) are considered to provide a risk reduction of privacy leakage. Based on the BlockTrust architecture, a blockchain-enabled tripartite anonymous identification trusted service provisioning (TriTrustServ) scheme is further proposed to guarantee a balanced tradeoff among the credibility, confidentiality, and efficiency in IIoT, including digital identity generation, anonymous access identification, and trusted resource provisioning. Note that for the sake of a high credibility in IIoT networks, a tripartite authentication is presented in this article with the first time among device manufacturer, devices, and network operator for the access process of device in IIoT networks. The feasibility and efficiency of BlockTrust architecture are experimentally verified in the realistic testbed, and the performances of the TriTrustServ scheme are evaluated by comparing with two benchmark schemes in the terms of average mistrust rate, resource utilization, and identification cost.

MoMA-LoopSampler: a web server to exhaustively sample protein loop conformations.

MoMA-LoopSampler is a sampling method that globally explores the conformational space of flexible protein loops. It combines a large structural library of three-residue fragments and a novel reinforcement-learning-based approach to accelerate the sampling process while maintaining diversity. The method generates a set of statistically likely loop states satisfying geometric constraints, and its ability to sample experimentally observed conformations has been demonstrated. This paper presents a web user interface to MoMA-LoopSampler through the illustration of a typical use-case. MoMA-LoopSampler is freely available at: https://moma.laas.fr/applications/LoopSampler/. We recommend users to create an account, but anonymous access is possible. In most cases, jobs are completed within a few minutes. The waiting time may increase depending on the server load, but it very rarely exceeds an hour. For users requiring more intensive use, binaries can be provided upon request. Supplementary data are available at Bioinformatics online.

Ciphertext Policy Attribute Based Encryption with Anonymous Access Policy

Ciphertext Policy Attribute Based Encryption with Anonymous Access Policy

The effect of blockchain on business intelligence efficiency of banks

PurposeAccurate evaluation of the consequences of new technologies in various industries is of great significance. So, it will be essential to examine the impact of this technology on the banking industry, representing how to create, deliver and gain value in this industry. This study aims to investigate whether blockchain can affect the business intelligence efficiency of banks. This study also aims to examine the impact of security, fraud reduction and privacy of blockchain, equal and anonymous access to the blockchain, decentralization and sustainability of blockchain, accountability and transparency of blockchain, quality, speed and efficiency of blockchain on business intelligence efficiency.Design/methodology/approachTechnological changes are creating new challenges and opportunities for various industries. The inability of organizations to adapt to these changes may even lead to their deletion from the market. Blockchain is one of the most critical technologies in recent years. One of the sectors that will undergo significant changes in blockchain technology is the banking industry. According to the reviewed literature in this study, a comprehensive model has been proposed to examine the impact of security, fraud reduction and privacy of blockchain, equal and anonymous access to the blockchain, the decentralization and sustainability of blockchain, accountability and transparency of blockchain and quality, speed and efficiency of blockchain on business intelligence efficiency. A survey method was used to collect data from banks of the Nanjing city. The partial least square technique was used for data analysis.FindingsThe results showed that the fit of the proposed model was very good. Also, all assumptions except one were confirmed. It means that security, fraud reduction and privacy of blockchain factor have a remarkable and positive impact on all aspects of business intelligence efficiency, namely information technology, employees, competitors and customers. Also, equal and anonymous access to the blockchain factor has a positive and significant effect on all aspects of business intelligence efficiency. The decentralization and sustainability of blockchain factors have an impact on business intelligence efficiency. Also, blockchain's accountability and transparency as a fourth factor have a positive and significant impact on all aspects of business intelligence efficiency. Finally, the last factor (quality, speed and efficiency of blockchain) has a positive and significant effect on information technology, employees and customers' dimensions. But, it does not affect the competitors' dimension, and this hypothesis has not been confirmed.Practical implicationsThis paper offers valuable insight for business intelligence practitioners into how blockchain technology has the potential to disrupt existing business intelligence provisions.Originality/valueThis paper is one of the first studies to examine the impact of blockchain on IT dimension, organizational employees' dimension, customer dimension and competitors' dimension. It lays a firm foundation for future research.

ABSAC: Attribute-Based Access Control Model Supporting Anonymous Access for Smart Cities

Smart cities require new access control models for Internet of Things (IoT) devices that preserve user privacy while guaranteeing scalability and efficiency. Researchers believe that anonymous access can protect the private information even if the private information is not stored in authorization organization. Many attribute-based access control (ABAC) models that support anonymous access expose the attributes of the subject to the authorization organization during the authorization process, which allows the authorization organization to obtain the attributes of the subject and infer the identity of the subject. The ABAC with anonymous access proposed in this paper called ABSAC strengthens the identity-less of ABAC by combining homomorphic attribute-based signatures (HABSs) which does not send the subject attributes to the authorization organization, reducing the risk of subject identity re-identification. It is a secure anonymous access framework. Tests show that the performance of ABSAC implementation is similar to ABAC’s performance.

Privacy-preserving biometric verification with outsourced correlation filter computation

In traditional biometric verification systems, personal computer stores biometric database and performs verification process. Because of limited storage, capacity, and computational power, both cloud computing and data centers provide these facilities for users and enterprises. However, shifting from user-owned and user-operated system to public and untrusted access services have raised concerns over data security, either in storage or computation phases. In this work, we propose a framework for fully privacy-preserving biometric verification with outsourcing computational tasks to the commerical public cloudsl. Firstly, privacy of the data used for biometric verification is preserved by encrypting training images. Secondly, for protecting the privacy of the biometric verification model, all correlation filter computation and verification stage are performed over encrypted biometric images in server side. Finally, privacy of the biometric verification result is preserved by sending it to the client for further investigation. Our solution provides anonymous access, unlinkability, and the confidentiality of transmitted data. I will be shown that our scheme is secure in the semi-honest server and has it reaches accuracy of 93.7% on facial dataset and 92% on fingerprint dataset.

Anonymous Access Monitoring of Indoor Areas

Video surveillance of public spaces is a feature of modern society that has expanded quite quickly and in a pervasive way during the last decades becoming a fundamental need for both individual and collective security. But, as the sophistication of this type of systems increases, the concern about threat to individuals’ right of privacy raises as well. Indeed, the video surveillance systems could breach personal privacy because location is clearly one of the most sensitive people information. Hence, preserving location privacy while achieving utility from it, is a challenging problem demanding the investigation of researchers. This paper tackles this non-trivial issue by designing a novel privacy-preserving architecture able to anonymously monitoring people access at the entrance of critical areas in an indoor space. At the same time our approach is able to provide full accountability in case of an accident or a legal requirement. Interestingly, our protocol is robust to server-side attacks and is efficient enough to be applied indoors through a set of IoT (Internet of Things) smart camera devices.