Anonymous Protocol Research Articles

Design and Implementation of an Anonymous and Secure Online Evaluation Protocol

Course evaluations have become a common practice in most academic environments. To enhance participation, evaluations should be private and ensure a fair result. Related privacy-preserving method and technologies (e.g., anonymous credentials, Privacy Attribute-Based Credentials, and domain signatures) fail to address, at least in an obvious way, the minimal security and practicality requirements. In this paper, we propose, evaluate, and implement an efficient, anonymous evaluation protocol for academic environments. The protocol borrows ideas from well-known and efficient cryptographic approaches for anonymously submitting ballots in Internet elections for issuing one-time credentials and for anonymously broadcasting information. The proposed protocol extends the above approaches in order to provably satisfy properties such as the eligibility, privacy, fairness and verifiability of the evaluation system. Compared to the state of the art, our approach is less complex and more effective, while security properties of the proposed protocol are verified using the ProVerif cryptographic protocol verifier. A web-based implementation of the protocol has been developed and compared to other approaches and systems.

An Anonymous Protocol with User Identification and Linking Capabilities for User Privacy in a Permissioned Blockchain

A permissioned blockchain includes a user in the network after verifying the user’s identity, in contrast to Bitcoin, which is a public blockchain that allows network participation without third-party approval. The two types of permissioned blockchains are private blockchains, each consisting of one server and multiple users, and consortium blockchains, which consist of groups of private blockchains. However, a blockchain has privacy issues, such as user tracking and inference. Therefore, cryptography should be applied for user privacy in a blockchain. There is a lot of research on anonymous protocols for privacy in a blockchain. In this paper, we provide a scheme for user management, i.e., identification and authorization, in a permissioned blockchain. We also propose an anonymous protocol with user identification and transaction linking capabilities provided by the private server, strictly to solve privacy concerns.

DPHI: An improved high-speed network-layer anonymity protocol

Abstract The Internet infrastructure has not been built with security or privacy in mind. As a result, an adversary who has control over a single Autonomous System can set-up mass surveillance systems to gather meta data by passively collecting the headers of the messages they route. To solve this problem, lightweight anonymous routing protocols such as LAP, DOVETAIL and most recently PHI have been proposed which are efficient enough to be deployed in a large scale infrastructure such as the Internet. In this paper we take a closer look at PHI and introduce several de-anonymization attacks malicious nodes can perform to reduce the sender and receiver anonymity. As a direct consequence of this analysis we propose a new protocol called dependable PHI (dPHI). The security analysis of dPHI includes a detailed quantitative anonymity analysis that compares dPHI with PHI, LAP and HORNET. Together with the performance analysis, this allows for a good comparison of trade-offs for these anonymity protocols.

Delegated content erasure in IPFS

The InterPlanetary File System (IPFS) is employed extensively nowadays by many blockchain projects to store personal data off-chain to comply with the Right to be Forgotten (RtbF) requirement of the General Data Protection Regulation (GDPR), the new regulatory regime for personal data protection in the EU. In such a way, when a request for content erasure is to be carried out under the RtbF, the onus of removing the actual personal information moves to the IPFS protocol. Nevertheless, enforcing data erasure across the entire IPFS network is not actually feasible, mainly due to its decentralized nature. Consequently, the implementation of a delegation mechanism for handling content erasure requests within the IPFS would be the most conducive way towards aligning the IPFS with the GDPR. To that end, in this work, we propose an anonymous protocol for delegated content erasure requests in the IPFS. The proposed protocol could be smoothly integrated into the IPFS to distribute an erasure request among all the IPFS nodes and, ultimately, to fulfil the erasure requirements foreseen in the RtbF. Furthermore, the protocol complies with the primary principle of the IPFS to prevent censoring; therefore, erasure is only allowed to the original content provider or her delegates. A formal definition and the security proofs are provided, along with a set of experiments that prove the efficacy of the proposed protocol. We demonstrate that the overhead introduced by the proposed protocol does not affect the system’s efficiency. Our experimental results exhibit a robust performance as the average times for generating the content-dependent keys and for spreading the erasure requests do not affect the overall performance of the IPFS.

An Efficient One-Way Authenticated Key Exchange Protocol for Anonymity Networks

Authenticated key exchange (AKE) is a crucial cryptographic primitive used for establishing an authenticated and confidential communication channel between parties, which has been widely used in our daily life when we surf on the Internet. However, in past decades mutual AKE protocols have been studied extensively in theory, while in many practical environments such as in the Tor anonymity network the mutual authentication property is undesirable. Meanwhile, considering privacy protection is getting more and more attention and one-way AKE protocols play an important role in privacy protection, so no matter in theory or in practice, it is quite meaningful to conduct research on the one-way AKE protocols. In this article, we present a new efficient anonymous one-way AKE protocol, which has strong anonymity and security properties guarantee, and efficiency advantages. Moreover, our new scheme has tight security reduction and is formally proved secure in the random oracle model under the Gap-DH and XCR signature security assumptions.

Reconciliation of Privacy with Preventive Cybersecurity: The Bright Internet Approach

The emergence of a preventive cybersecurity paradigm that aims to eliminate the sources of cybercrime threats is becoming an increasingly necessary complement to the current self-defensive cybersecurity systems. One concern associated with adopting such preventive measures is the risk of privacy infringement. Therefore, it is necessary to design the future Internet infrastructure so that it can appropriately balance preventive cybersecurity measures with privacy protections. This research proposes to design the Internet infrastructure using the preventive cybersecurity measures of the Bright Internet, namely preventive cybersecurity protocol and identifiable anonymity protocol, and ten privacy rights derived from Europe’s General Data Protection Regulations (GDPR). We then analyze the legitimacy of the five steps of the preventive cybersecurity protocol and the four features of the identifiable anonymity protocol from the perspectives of ten privacy rights. We address the legitimacy from the perspective of potential victims’ self-defense rights. Finally, we discuss four potential risks that may occur to the innocent senders and proposed resilient recovery procedures.

An enhanced anonymous authentication protocol for wireless sensor networks

Nowadays, wireless sensor networks (WSNs) have played important roles in a variety of areas. However, the nature of wireless communications and restricted resources make it more likely to suffer from various kinds of attacks. As to this problem, many authentication protocols have been proposed recently to secure the communications in WSNs. Among these schemes, Singh et al.'s protocol shows great novelty. Unfortunately, we find in our current research that Singh et al.'s protocol still has the vulnerabilities to stolen/lost smart card attacks, privileged-insider attacks, the session key leakage attacks, and so on. To solve these problems, we first propose an enhanced anonymous authentication protocol by using Hash function and bitwise XOR operations based on Singh et al.'s protocol. Secondly, we conduct detailed security analysis to the proposed authentication protocol, and make security-feature comparisons with related protocols. In addition, we give formal proof and security verification of the proposed protocol by using Burrows-Abadi-Needham (BAN) logic and AVISPA tool, respectively. Finally, we give performance comparisons in terms of computing costs and communicating costs, respectively. Comparative summaries demonstrate that our protocol provides more extractive features and security guarantees with little increased overheads.

A secure three factor-based fully anonymous user authentication protocol for multi-server environment

A single sign-on authentication scheme is required protocol in multi-server environment. Recently, an authentication protocol based on Lagrange interpolation polynomial to satisfy multi-server environment with low computational and communication cost is proposed. In this paper, we have analysed the above scheme and show that their scheme is vulnerable to various attacks like insider attack, server impersonation attack, user impersonation attack and stolen smart card attack. We also show that their scheme fails to provide server anonymity, user revocation in case smart card is lost/stolen or users authentication parameters are revealed. We have also proposed enhanced multi-server authentication protocol using biometric-based smart card and Lagrange interpolation which is more secure. The proposed protocol is analysed using BAN logic to show that the proposed protocol provides secure authentication. In addition, we have simulated our scheme using widely accepted and used AVISPA tool to prove that our scheme is secure against passive and active attacks. The proposed protocol provides high security and anonymity along with low communication and computational cost and various security functions.

A secure and privacy-preserving key agreement and mutual authentication scheme

The development of manufacturing, communication, and computing technologies has promoted convergence of different network architectures, aiming to make full use of all resources to create valuable information. While heterogeneous integrated networks play a key role in providing highly effective and efficient solutions for medical users, they also raise various security and privacy issues. Strengthen the security and privacy protection and efficiency before transmitting sensitive data is a primary challenge to be addressed. Traditional authentication methods fail to differentiate the privacy sensitivity difference between data collected by distinct devices. We propose a secure and efficient key management scheme based on a key-exposure resistant chameleon hash function. Through adopting the devices' privacy sensitivity and users' attribute credential as two factors to establish trust between different entities, we proposed a secure and anonymous authentication protocol. The security analyses indicate that the proposed protocol can satisfy security requirements.

A provably secure pairing-free anonymous handover authentication protocol for mobile wireless networks

A provably secure pairing-free anonymous handover authentication protocol for mobile wireless networks

Anonymous communication scheme based on quantum walk on Cayley graph

Information security is the cornerstone and lifeblood of national security in the information society, and anonymous quantum communication is one of the important ways to protect information security. Using quantum walk randomness to effectively solve sensitive problems such as leakage of identity information. In this paper, an anonymous communication scheme based on quantum walks on the Cayley graph is proposed. First, both parties in the communication hide their identity information, and the sender Alice anonymously selects the receiver Bob through logic or operation. Secondly, the trusted third party and the communicating parties use the BB84 protocol to generate and distribute the security key. Alice encrypts the information sequence according to the security key to obtain the blind information; Bob uses the joint Bell state measurement and security key to sign and the trusted third party verifies the signature information. Third, the trusted third party calculates the position probability distribution function of Bob’s quantum walk via the Fourier transform, converts the position information corresponding to the maximum probability into a confirmation frame and sends it to Alice; Alice uses the quantum compression algorithm by decreasing dimensions to reduce the number of transmitted information bits(the length of the information bit can be reduced by up to 37.5%) and uses the security key to complete the information encryption and then transmit the information to the location indicated by the confirmation frame. Bob uses quantum walks to search the location node to obtain the transmission information and complete the anonymous quantum communication. Finally, the security analysis of the scheme is carried out, and the numerical simulation results of the Cayley graph of 200 nodes are given. At the 10-step walk, the maximal probability of the 6th node is 45.31%. According to the simulation results, the probability that Bob is eavesdropped on the specific location at his 10-step walk during the communication of this scheme is approximately 6 × 10<sup>–7</sup>%, so the receiver can avoid the identity information from the eavesdropping with a high probability, and the quantum network anonymity protocol is not broken.

Why elliptic curve Diffie-Hellman (ECDH) is replacing Diffie-Hellman (DH)

The Elliptic Curve Diffie-Hellman is an anonymous key agreement protocol that allows two parties, each having an elliptic-curve public-private key pair, to establish a shared secret over an insecur...

Quantum correlations for anonymous metrology

We introduce the task of anonymous metrology, in which a physical parameter of an object may be determined without revealing the object's location. Alice and Bob share a correlated quantum state, with which one of them probes the object. Upon receipt of the quantum state, Charlie is then able to estimate the parameter without knowing who possesses the object. We show that quantum correlations are resources for this task when Alice and Bob do not trust the devices in their labs. The anonymous metrology protocol moreover distinguishes different kinds of quantum correlations according to the level of desired security: discord is needed when the source of states is trustworthy, otherwise entanglement is necessary.

Information leakage of multi-threaded programs

Quantitative information flow is an important technique for measuring information leakage of a program. It is widely used in analyzing anonymity protocols and timing channels. One area of interest is to quantify the information leakage of multi-threaded programs, which has not been well-studied in prior work. In this paper, an automated trace-based approach is proposed to precisely quantify information leakage of shared-memory multi-threaded programs. The approach takes into account the effect of schedulers and leakage in intermediate states of executions. The programs are modeled by Markovian processes. Then, variants of information leakage, including expected, bounded time, maximum, and minimum leakages are measured. The validity of the approach is demonstrated by implementing it in a tool PRISM-Leak, which is built upon PRISM, a probabilistic model checker. Finally, two case studies are utilized to analyze and compare the approach against state-of-the-art leakage quantification tools.

Adaptive Risk Prediction and Anonymous Secured Communication in MANET for Medical Informatics.

Location-based services (LBS) and information security is a major concern in communication system.With the increasing popularity of location based services more attention is paid to preserve location information to protect the data. In order to protect and preserve the MANET and location based services, there are various existing location based anonymity protocols such as k-anonymity location based, but these protocols are more overhead due to the dynamic mobility nature of ad-hoc networks. In this paper we proposed an Adaptive Risk Prediction and Anonymous Secured Communication protocol to predict the risk before processing anonymous communication. The proposed protocol estimates the risk against adjacent nodes and estimates the vulnerability paths using hidden markov model and decision tree. The decision tree determines the evidence to identify the trusted paths. The anonymous communication message authentication scheme assigns the anonymous communication and organize the secured authentication scheme. We simulated the network by considering different attacks to determine the efficiency of Adaptive Risk Prediction and Anonymous Secured Communication using NS2 simulator.

Are Role and Gender Related to Sexual Function and Satisfaction in Men and Women Practicing BDSM?

BackgroundPublished studies show good psychological health of people involved in bondage-discipline, dominance-submission, and sadism-masochism (BDSM) activities; nevertheless, there are few studies on characteristics related to gender, role in the BDSM scene, sexual functioning, and satisfaction among BDSM practitioners. AimThe aim of this study was to explore gender and role differences, prevalence of sexual complaints, related distress, and sexual satisfaction in BDSM participants compared with the general population. MethodsA group of 266 Italian consensual BDSM participants (141 men and 125 women) were recruited with a snowball sampling technique. An anonymous protocol, including self-reported ad hoc and validated questionnaires, was used. The control group was composed of 100 men and 100 women who were not significantly different from the BDSM group for the sociodemographic data and were randomly extracted from an Italian database on sexual functioning of the general population. Main Outcome MeasuresSelf-reported demographic factors, including favorite and most frequent BDSM practices, the Sexual Complaint Screener, and the Sexual Satisfaction Scale, were completed by the participants. ResultsThe mean age of the BDSM group was 41.42 ± 9.61 years old (range 18–74). Data showed a varied outlook of practices, fantasies, rules, and roles. With regard to concerns about BDSM activities (fantasies and behaviors), participants reported a very low self-declared degree of distress. The dominant and switch groups appear to be more satisfied and less concerned about sexuality than the general population and the submissive group. Role in the BDSM scene was the only significant predictor of sexual satisfaction, showing a medium effect size. Clinical ImplicationsResults from this study could be helpful to inform sexual health care professionals and to reduce the stigma related to the BDSM population. Strengths & LimitationsIn general, this study may help to describe better some characteristics related to gender, role, sexual preferences, function, and satisfaction. The main limitation regards the sampling method, which does not allow us to consider the group as representative of BDSM participants in general. ConclusionData showed a varied outlook of practices, fantasies, rules, and roles in both BDSM men and women. BDSM participants (especially dominant and switch groups) appear to be more satisfied and less concerned about sexuality than the general population. This is an attempt to increase the attention of researchers and health care professionals to this important topic and to improve the care provided to people with specific preferences and behaviors.Botta D, Nimbi FM, Tripodi F, et al. Are Role and Gender Related to Sexual Function and Satisfaction in Men and Women Practicing BDSM? J Sex Med 2019;16:463–473.

Reconsidering a lightweight anonymous authentication protocol

ABSTRACTIn the cryptographic community, many efforts have been expended to build secure authentication protocols without using heavy asymmetric encryption. However, many of these efforts were ineffectual because many of them were found insecure due to low robustness to different types of attacks. This paper identifies a particular type of an attacker model that will never allow a secure lightweight authentication protocol. We demonstrate this finding by breaking a recently proposed protocol that is fixed from two insecure protocols. Then, we present the arguments for the impossibility of the existence of such a protocol while a secure protocol can appear only in an augmented version of this attacker model.

A Survey on Measuring Anonymity in Anonymous Communication Systems

The popularity of Internet applications has made communication privacy an increasingly important security requirement. As an important aspect of privacy, anonymity ensures that a subject may use resources or services without disclosing user identity or corresponding relationships. Since the seminal work by Chaum for anonymous communication, many different anonymous communication systems, and anonymous protocols have been developed and investigated extensively. In recent years, anonymous communication systems have evolved from academic tools used by specialists to mass-market software used by millions of ordinary people. How to evaluate and quantify the anonymity that different anonymous communication systems can offer has been a new focus. Though some efforts have been made on anonymity metrics and measuring techniques, systematic research on measuring anonymity of anonymous communication systems is still needed. In this paper, we give a comprehensive overview of state-of-the-art research on measuring anonymity. We first summarize the anonymous mechanisms applied by different anonymous systems. We then introduce the formalization of the notion of anonymity for measuring the anonymity degree. Further, metrics based on various theories and approaches are reviewed. We particularly elaborate on the metrics based on information theory as a separate section because of its popularity and multiple branches. The metrics based on information entropy is probably of the greatest interest.

Traffic analysis of anonymity protocol using hidden Markov model based on the model confidence

Traffic analysis of anonymity protocol using hidden Markov model based on the model confidence

Anonymous roaming authentication protocol for wireless network with backward unlinkability, exculpability and efficient revocation check

Secure seamless roaming in a wireless network is desirable in today’s highly dynamic world. Providing revocation and non-traceability in an efficient two-party roaming authentication protocol is a challenging task. Conventional two-party protocols utilize pseudo-identities or group signature with revocation tokens to support non-traceability and strong user anonymity. Among the group signature based authentication schemes, only Priauth scheme has non-traceability or backward/forward unlinkability and the mobile user does not have to do any computation after each revocation. Despite all the advantages, Priauth scheme does not support exculpability or in other words the home server knows the group signing key of the mobile user. In case of dispute, the mobile user can deny that it generated signature because the mobile user and the home server both know the signing key of the mobile user. Thus, the mobile user cannot be held accountable. Moreover, Priauth has high revocation cost due to pairing operation performed for each revoked token in the revocation list during revocation checking at the foreign server. In addition, the existing group signature based authentication schemes are not provably secure in the random oracle model. We propose a provably secure two-party authentication protocol using group signature scheme which overcomes the weaknesses of Priauth scheme by supporting exculpability, backward unlinkability and using exponential operation instead of costlier pairing operation during revocation checking.