Anonymous Communication Research Articles

An efficient certificateless anonymous signcryption communication scheme for vehicular adhoc network

Certificateless public key infrastructure (PKI) avoids the key escrow problem associated with identity-based PKI and has recently been widely employed in anonymous communication schemes for vehicular adhoc networks (VANETs). In existing certificateless anonymous signcryption schemes for VANETs, vulnerabilities such as potential attacks involving the substitution of pseudonyms and the forging of pseudonymous public-private key pairs exist due to the lack of “identity-key binding” and “non-linearity processing of public-private key pairs.” To address this issue, we propose an improved certificateless anonymous signcryption scheme based on elliptic curve cryptography. The scheme incorporates bilinear pairing as one of the authentication mechanisms, designs pseudonym generation algorithms and public-private key pair structures, and introduces a pseudonym verification mechanism. The correctness of the scheme is proven under the random oracle model, and its security is extensively demonstrated through detailed discussions on its confidentiality, authentication, unforgeability, anonymity, and traceability. Furthermore, the time and space complexity of the scheme are calculated. By comparing with recently published certificateless signcryption schemes, it is shown that the proposed scheme offers higher security with smaller computational and communication overheads. This certificateless vehicular network signcryption algorithm provides an efficient encryption solution for anonymous communication in vehicular networks, thereby ensuring the rapid development of secure technology for intelligent connected vehicle super terminals.

Managing a 4000-participant cohort with a novel mobile app: data from the RisCoin study in Germany

Abstract Issue RisCoin, a prospective monocentric longitudinal observational study, aimed to identify risk factors for COVID-19 vaccine failure. Secondary aim is to monitor symptoms, SARS-CoV-2 infection, vaccination status of 3816 enrolled healthcare workers (HCW) and 180 patients with inflammatory bowel disease (IBD). Since the LMU University Hospital Munich served both as study sponsor and employer of the HCW, a secured approach was required. Description of the solution Participants accessed the study app (CentraXX, KAIROS GmbH, Germany) via pseudonymized Contact-ID with irreversible anonymization after 6 months. Key app features were the serological results report, bidirectional messaging, and weekly survey for self-reported data on vaccinations, infections, and symptoms. Active app use was defined as submitting >1 weekly survey during the study period 10.2021-12.2022. Results Over 15 months, our study team maintained 1964 two-way communications with 958 participants via the app. Of 3979 participants with app access, 3622 (91%) were active users, 2606 (65%) submitted 1 to 11 surveys, 1016 (26%) made ≥12 submissions (P75, “frequent users”). Frequent users were more likely to be IBD patients (p = 0.001), female (p < 0.001), aged 60 or older (p < 0.001). Staff in administration and nurses were more likely to be frequent users compared to physicians (p < 0.001). Main problems included the initial operational system disparities resulting in app crashes and continuous need for app reactivation. Both led to loss of active participants and required substantial staff resources to onboard and support participants during the study. Lessons The study app enabled secure, flexible, bidirectional communication with all participants. Despite technical issues, the majority actively used the app and provided valuable longitudinal data through weekly survey submissions. Key messages • A study-specific app provides a flexible and secure bidirectional anonymous communication for the study team and participants. • Adherence to app-based communication and data collection for pandemic monitoring was particularly high among patients, nurses and administrative staff.

Are continuous stop-and-go mixnets provably secure?

This work formally analyzes the anonymity guarantees of continuous stop-and-go mixnets and attempts to answer the titular question. Existing mixnet based anonymous communication protocols that aim to provide provable anonymity guarantees rely on round-based communication models, which requires synchronization among all the nodes and clients that is difficult to achieve in practice. Continuous stop-and-go mixnets (e.g., Loopix and Nym) provide a nice alternative by adding a random delay for each message on every hop independent of all other hops and all other messages. The core anonymization technique of continuous mixnets combined with the fact that the messages are sent by the clients to the mixnet at different times makes it a difficult problem to formally prove security for such mixnet protocols; existing end-to-end analyses for such designs provide only experimental evaluations for anonymity and were lacking a comprehensive formal treatment. We are the first to close that gap and provide a formal analysis. We provide two indistinguishability based definitions (of sender anonymity), namely pairwise unlinkability and user unlinkability, tuned specifically for continuous stop-and-go mixnets. We derive the adversarial advantage as a function of the protocol parameters for the two definitions. We show that there is a fundamental lower bound on the adversarial advantage $\delta$ for pairwise unlinkability; however, strong user unlinkability (negligible adversarial advantage) can be achieved if the users message rate ($\lambda_u$) is proportional to message processing rate ($\lambda$) on the nodes.

A blind flow fingerprinting and correlation method against disturbed anonymous traffic based on pattern reconstruction

Tor is the most widely used anonymous communication system at present which can anonymize users’ network behavior. At the same time, many illegal network activities also appear more frequently with the help of Tor, posing serious challenges for cyberspace security. Therefore, flow fingerprinting and flow correlation analysis methods are put forward to de-anonymize the malicious anonymous behaviors, which utilize external traffic features as the side-channel information. However, the adversary often reduces the ability of above two methods by adding the disturbance to the anonymous traffic. As a countermeasure against the interference, disturbance-resistant analysis methods can effectively identify those adversarial behaviors while knowing how the traffic is modified. However, in real scenarios, it is unrealistic to distinguish between disturbed and non-disturbed anonymous traffic, let alone to have a clear grasp of the disturbing strategy. In this paper, we propose a blind anonymous traffic analysis method called Blind Analyzer based on pattern reconstruction skills in a “masking-generation” manner. Specifically, Blind Analyzer extracts the pattern knowledge from non-disturbed traffic samples by masking and reconstructing them. During the method application, disturbed anonymous traces are processed following the same way, aiming at removing the incremental noise at the masking stage and restoring the original shape at the reconstruction stage. Besides, a conditional discriminator is designed to determine whether the generated sample has obvious class characteristics. Benefited from the proposed method, we can improve the effectiveness of the anonymous network behavior analysis since the disturbed traffic can be restored as normal ones accurately enough. Experiment results on three datasets show that reconstructed traffic samples output by Blind Analyzer are more useful for base analysis models, which improve the corresponding metric values by 11.23% and 6.61% in max for flow fingerprinting and correlation tasks, respectively.

Technical Anonymity and Employees’ Willingness to Speak Up: Influences of Voice Solicitation, General Timeliness, and Psychological Safety

Purpose: In recent years, many enterprises have established anonymous online forums to encourage employees to speak up. However, questions remain regarding whether these anonymous communication channels work. This research explores how and when technical anonymity influences employees’ willingness to speak up. Design/methodology/approach: Via an experimental method (study 1), we investigated the effects of technical anonymity and the moderating effects of voice solicitation. Via an experimental method (study 2), we examined the effects of technical anonymity and the moderating effects of time delay. Findings: The results of two studies consistently indicate that employees are more willing to speak up in the anonymous condition than in the nonanonymous condition and that psychological safety mediates the relationship between technical anonymity and employees’ willingness to speak up. In addition, we identify the boundary conditions of the effects of technical anonymity. In the prohibitive voice solicitation condition and in the delay condition, the above effects exist. Originality/value: First, we contribute to the literature on organizational media affordance by examining the effects of the anonymity affordance. Second, we contribute to the literature on organizational anonymity communication by exploring the impacts of technical anonymity on employees’ willingness to speak up in the workplace. Third, we extend the literature on employee voice by theorizing and demonstrating the moderating roles of two novel variables.

Design of a mix network with elliptic curve cryptography and XOR shuffling for secure communication with 5‐node

AbstractThis research paper proposes a novel 5‐node mix network, an anonymous communication network to boost privacy within the network. Within the proposed framework the crypto‐operations like encryption, decryption, and shuffling are held with the help of the Elliptic Curve Cryptography (ECC) and XOR algorithm. This unique combination helps to exchange the message within the communication network with enhanced security and privacy. To analyze the processing time and load factor at each intermediate node of mix network, an exhaustive experimental analysis is carried out for key sizes of 256, 384, and 512 bits respectively. These crypto‐operations like encryption, decryption, and XOR shuffling need varying time slots to perform at each intermediate node thereby having a varying load factor associated with them. The objective of this research is to analyze the processing time and load factor at each node within the 5‐node mix network thereby helping to analyze the strengths and weaknesses of each intermediate node. Through our analysis, these percentages are computed, shedding light on the allocation of computational load and resource utilization among the nodes.

Develop a Mathematical Model to Secure Anonymous Communication in Manet Through Cluster Framework

Develop a Mathematical Model to Secure Anonymous Communication in Manet Through Cluster Framework

A Novel Authenticated Quantum Anonymous Secret Sharing for Classical and Quantum Information

AbstractAnonymous secret sharing (ASS) is an essential cryptographic concept that facilitates the sharing and reconstruction of secret information while safeguarding the identity of the involved secret receivers, which has broad applications in key management, data backup, and distributed systems. In this study, a novel authenticated quantum anonymous secret sharing (QASS) protocol that emphasizes information privacy and identity anonymity protection is proposed. Employing ‐level multipartite GHZ states as a quantum resource, one‐sided anonymous entanglement (AE) is innovatively established between the dealer and anonymous receivers, enabling the dealer to distribute a random share of secret information. Additionally, by establishing a one‐sided AE between anonymous receivers and restorer, the restorer can securely collect and reconstruct the secret information using quantum teleportation (QT). Rigorous security analysis demonstrates that protocol can resist attacks from active adversaries and potentially dishonest users. Quantum experiments on IBM Qiskit validate the correctness and feasibility of the proposed QASS protocol. This work contributes to the advancement of quantum anonymous communication, addressing the requirements for information privacy and identity anonymity in practical application environments.

Online paedophiles and the criminal justice experience: A qualitative perspective

BackgroundOnline forums provide a conduit for anonymous communication within deviant subcultures, such as online paedophiles. This helps to build virtual communities of support. ObjectiveThis study explores the experience of paedophiles in the criminal justice system as reported by those who experienced it on such a forum. By analysing and understanding the experiences disclosed by these individuals, we may be able to design more targeted prevention strategies and treatment options.Participants and Setting.Data are from one online forum discussion thread that includes 595 online forum posts by 212 unique usernames ranging over 11 years from 2012 to 2023. This forum claims to be an anonymous “therapeutic community” for paedophiles and does not allow the sharing of media (e.g., videos or images). MethodsThis study uses an inductive approach to analyse the posts and discover the perspective and concerns of users who have experienced or are faced with prosecution and punishment. ResultsSeven main themes emerged from the posts on this thread: support and praise, techniques of neutralisation, life in prison, anxiety and mental health, relationships, therapy, and difficulties post-prison. ConclusionsThe forum provided an important source of support among a virtual community of people who shared similar sexual interest in children and feel rejected and demonised by mainstream society. The thread functioned like an “echo chamber” that reinforced a positive view of users' deviant interest. Individuals who had been prosecuted for their offending were returning to the forum, which may encourage reoffending. Parole boards and probation officers may need to consider limiting or restricting access to the Internet, particularly the Tor network, when setting release conditions. Implications for treatment focus on challenging the justifications and excuses used by paedophiles.

A lightweight anonymity protocol at terabit speeds on programmable switches

Anonymous communication protocols are integral tools for people to exercise the right to privacy in their online activities. Such tools are urged to offer maximum protection against various classes of adversaries, including rogue criminals, exploitative companies, and authoritarian or paternalistic regimes, while respecting the diversity of users’ activities, from e-mail and web browsing to file transfer and video streaming. In such a context, lightweight anonymity protocols are a promising solution to provide well-balanced anonymity and performance for daily use against a class of adversaries with a relaxed but realistic assumption of their capability. However, as the existing instantiations of these protocols solely target software implementation, they did not fully exhibit their advantages in performance by the relaxation of the adversarial model. This paper presents P5HI, a novel instantiation and implementation of a lightweight anonymity protocol on hardware programmable switches. Its realization requires a rethinking of all aspects of the system, beginning with the realization of bit-rotation on the switch, through the construction of a cryptographic scheme and attack prevention, to hardware-friendly procedures during path setup and data transmission. We deploy the full-fledged design of the lightweight anonymity protocol on an actual programmable switch, and our prototype demonstrates its operation at a speed of over 3.0 Tbps.

Komunikasi Tanpa Nama yang Jujur dan Terbuka : Studi Kasus pada Akun @Komunitasmaunangisaja di Twitter (X)

This study analyzes the phenomenon of anonymous communication on the Twitter account (X) @komunitasmaunangisaja and its impact on users' mental health using a transcendental phenomenology approach. Data collection methods include direct observation, content analysis of tweets, and in-depth interviews with account users. Findings indicate that anonymous communication on this account positively impacts mental health by reducing feelings of isolation and enhancing emotional well-being. Users feel more free to express their feelings without fear of judgment, helping to alleviate emotional burdens and gain community support. However, there are also negative impacts, such as dissatisfaction with received responses and the risk of anonymity abuse for negative behavior. The study also reveals that users frequently turn to anonymous communication to cope with stress, anxiety, and depression. This platform provides a space for sharing deep emotions and experiences, facilitating a sense of togetherness and emotional release. Community support helps users feel validated and understood, contributing to overall mental health improvement. This study highlights the importance of such platforms in creating a safe environment for emotional expression, ultimately contributing to better mental well-being, and emphasizes the need for more supportive online communities

Multi-participant quantum anonymous communication based on high-dimensional entangled states

Anonymous quantum communication (AQC) enables the secure transmission of quantum or classical messages between a sender and a receiver while ensuring the anonymity of their identities. Existing AQC protocols primarily address one-to-one anonymous communication. When there are multiple senders, they must send their messages sequentially to avoid collision problems. In this paper, we propose a multi-participant quantum anonymous communication (MQAC) by employing high-dimensional entangled states. In this protocol, multiple senders establish anonymous entanglement with multiple receivers of their choice and send quantum messages anonymously and simultaneously via quantum teleportation. To propose MQAC, we first present the toolbox we developed, which includes several sub-protocols such as the verification protocol, collision detection protocol, address distribution protocol, and notification protocol. These sub-protocols, which we propose, not only are important parts of MQAC but also serve as the foundation for solving many more complex tasks, such as anonymous commodity transaction. Additionally, the analysis of MQAC demonstrates that neither internal nor external attackers can steal the identities of the communication parties or the transmitted messages by employing any attack. Our work represents an original exploration of anonymous message transmission between multiple senders and receivers in quantum networks.

Cybersecurity in Onion Routing Environments: Strategies to Thwart Cyber Threats

Onion routing networks, or darknets, enable anonymous communication, protecting user privacy and attracting cybercriminals. This paper analyzes cybercrime in these networks, including drug trafficking, fraud, and hacking. The challenges seen in the detection and mitigation of these crimes arising as the result of strong anonymity and explore countermeasures such as law enforcement, technological solutions, and policy interventions have been discussed, as also highlighting of the limitations of current measures and proposals for future research, with emphasis on the need for interdisciplinary approaches combining technical, legal, and social perspectives.

Evaluating the Impact of Internet Users' Emotional Tendencies on Opinion Dynamics through Computer-Assisted Sentiment Analysis of Texts

- Internet communication is characterised by "non-linear flow" and "unorganised aggregation," and computer-assisted text sentiment analysis is an important means of evaluating the impact of netizens' emotions on the dynamics of public opinion. The uncertainty, anonymity, disorder, and blindness inherent in fast-gathering and fast-dispersing Internet communication drive the continuous generation of texts, which has an important impact on public opinion. In order to study this issue in depth, this paper chooses two text types of "popular Weibo" and "popular topics" in Sina Weibo as the object of study and analyses the issue in detail from the two dimensions of agenda construction and agenda setting. In the process of the study, the required text data were collected through Python, and the theoretical assumptions were verified with text analysis methods to explore the influence of text sentiment bias on opinion diffusion, with a view to providing new insights and references for the application of the theory of opinion diffusion and the field of computational diffusion.

PEER-TO-PEER AUDIO STREAMING USING THE TOR NETWORK: PROBLEMS, OPPORTUNITIES AND DEVELOPMENT PROSPECTS

This article analyses the potential and challenges associated with the implementation of audio streaming in the anonymous Tor network and the use of peer-to-peer (P2P) technologies. The main focus is on discussing the technical and conceptual issues that arise when integrating audio streaming services with the Tor network, including delays, limited bandwidth and other limitations that affect audio quality. The aim of the study is to find practical solutions to the problem of anonymous audio streaming using Tor technologies or other means to preserve anonymity. By analysing different approaches and tools, it becomes apparent that peer-to-peer broadcasting offers a flexible solution that allows audio to be transmitted over P2P networks, reducing the load on individual nodes and optimising bandwidth usage. This solution offers opportunities for scalability, fault tolerance, bandwidth optimisation and latency reduction, making it an attractive option for audio streaming setups. Meanwhile, the Utopia ecosystem, with its decentralised structure and high level of privacy protection, is another potential solution. Not only does it allow bypassing censorship and firewalls, but it also ensures anonymity in communication and data exchange. With its built-in audio and video communication tools, as well as the ability to create private channels and share files, Utopia can become a reliable platform for streaming audio. Thus, based on the analysis, the solution to the problem of anonymous audio streaming may lie in the integration of technologies such as Peercasting and Utopia, which provide not only the technical capability for streaming, but also a high level of privacy protection for users. It is also important to consider the flexibility of these solutions and the ability to adapt to the specifics of anonymous networks and user requirements. The practical significance of the study of audio streaming over Tor using P2P technologies is to develop methods to increase the anonymity and security of audio communications, which is critical in the face of growing threats to privacy on the Internet. This allows to overcome censorship and Internet restrictions in repressive regimes, providing users with freedom of thought and access to information.

Phishing for Nazis : Conspiracies, Anonymous Communications and White Supremacy Networks on the Dark Web

Phishing for Nazis : Conspiracies, Anonymous Communications and White Supremacy Networks on the Dark Web

A Framework for Provably Secure Onion Routing against a Global Adversary

Onion routing and mix networks are a central technology to enable anonymous communication on the Internet. As such, a large number of protocols and model variants have been explored in the field, which offer differing levels of privacy, exhibit vulnerabilities, or even supersede each other. These factors make discovering the appropriate formalization for new developments difficult, and some model variants have not been formalized at all. We address this issue by creating one parametrized framework that encompasses the onion routing and mix network models and functionalities with a global adversary in the related work. In doing so, we create a categorization of the variants of onion routing models in use in the related work and map common OR and mix network protocols to their variants. For each identified variant: Our framework offers i) an ideal functionality in the Universal Composability framework, and ii) game-based properties that imply realization of the ideal functionality when a protocol satisfies them. In effect, our framework both unifies and extends previous formalization efforts in the field.

MixMatch: Flow Matching for Mixnet Traffic

Mixnets provide communication anonymity against network adversaries by routing packets independently via multiple hops, delaying them artificially at each hop, and introducing cover traffic. We show that these features (particularly the use of cover traffic) significantly diminish the effectiveness of state-of-the-art flow correlation techniques developed to link the two ends of a Tor connection. In this work, we propose novel methods to determine whether a set of endpoints exchanges packets via a mixnet and demonstrate their effectiveness by applying them to the Nym mixnet. We consider Nym in both an idealized lab setup and the official live network, and propose and compare three classifiers to conduct flow matching on it. Our statistical classifier tests whether egress packet timestamps are consistent with ingress timestamps and the (known) routing delay characteristic of the mixnet. In contrast, our two deep learning (DL) classifiers learn to distinguish matched from unmatched flow pairs from collected datasets directly, rather than relying on priors that describe the delay distribution. All three classifiers use our flow merging technique, which enables testing a match for sets of communicating endpoints of any cardinality. Considering a use case where two observed endpoints communicate exclusively to exchange a file through Nym, we find that flow matching is fast and accurate in the idealized lab setup. If flow pairs are aligned using all network observations in a download, we achieve a TPR of circa 0.6 (DL) and 0.47 (statistical) at an FPR of 10^-2 after only processing 100 observations. We evaluate classifier performance under key variations of this setup: the absence of loop cover traffic, an increased or decreased average per-mix delay, larger communicating sets (three endpoints) with faster responders, and the presence of realistic network effects (live network). The classifiers' matching performance diminishes on the live network where packet losses and variable propagation delays exist, reducing DL TPR to circa 0.26 and statistical TPR to circa 0.28 at an FPR of 10^-2. Informed by the insights of our analyses, we outline countermeasures that can be deployed in mixnets such as Nym to mitigate flow matching threats.

AET: Implementing Anonymity Enhancing Techniques for MANETs Using Statistical Traffic Analysis

Anonymous communication is the main issue in case of MANETs. It is difficult to find the source and destination of the communication link and the other nodes involved in it. Many anonymity enhancing techniques have been proposed based on packet encryption to protect the communication anonymity of mobile ad hoc networks (MANETs). However, MANETs are vulnerable under certain circumstances like passive attacks and traffic analysis attacks. Here we describe the traffic analysis problem, expose some of the methods and attacks that could infer MANETs are still weak under the passive attacks. To show how to discover the communication patterns without decrypting the captured packets, we present the paper AET using statistical traffic analysis.

WF3A: A N-shot website fingerprinting with effective fusion feature attention

Tor anonymity communication system provides privacy to users while also allowing sensitive users to access illegal websites. Website fingerprinting (WF) attack is a technique employed to identify websites visited by users, serving as a crucial tool for effectively recognizing user access to illegal online content. However, the majority of existing WF methods heavily rely on extensive training data, which faces challenges when dealing with more common few-shot scenarios which involve limited traffic traces. In such circumstance, these methods often fall into low accuracy in face of the absence of sufficient samples. Therefore, a N-shot WF recognition method with effective fusion feature attention (WF3A) is proposed in this paper. Different from the conventional single-feature recognition method, we innovatively combine direction and length, design and use the fusion feature that covers more website identification information; In order to interpret the traffic patterns that can identify the website categories from the fusion feature, we introduce the Enhanced Channel Attention (ECA) and design a stronger feature extractor when constructing WF model, which enhances the learning ability of the model by channel attention mechanism. The experimental results indicate that fusion feature outperforms original feature in few-shot scenarios. Furthermore, the proposed WF3A demonstrates superior performance compared to existing WF method. In the closed-world, the classification accuracy of WF3A is enhanced by 3.86% to 56.3% compared to existing methods. In the open-world, when the recall is controlled at 91.43%, the precision still remains stable at 81.16%.