Important Security Properties Research Articles

Selective comparison of verifiable online voting systems

AbstractThis paper aims to provide a guideline for identifying the most suitable online voting system under the given requirements and acceptable tradeoffs. We have selected twelve (more or less) well‐known online voting systems that rely on distinct cryptographic mechanisms for achieving security. For each of the systems, we summarized the key architectural and cryptographic ideas behind their design. Then, we analyzed the required trust assumptions for achieving the three most important security properties (i.e., verifiability, divided between cast‐as‐intended, recorded‐as‐cast, and tallied‐as‐recorded verifiabilities, privacy, and receipt‐freeness). To make a fair comparison, we did our analysis based on identical security definitions. Note that we selected wildly known and well‐accepted definitions, which are scheme‐neutral, to avoid any biases. Also, we discussed some of the most critical practical aspects of those systems, such as–the necessity for secure or anonymous channels, reliance on secure printer facilities and so forth. To facilitate the comparison, we suggested a unified naming convention for system elements based on their roles and functions. Then, based on the unified naming convention, we compared all twelve online voting systems for both the security properties and practical aspects. Finally, we summarized our observations regarding patterns and dependencies we observed, provided guidelines for selecting the online voting system, and gave recommendations regarding system design. We hope our work contributes to the online literature and facilitates the process of selecting the most suitable e‐voting system depending on the requirements of a specific election.

Threshold secret sharing with geometric algebras

In this work, we propose a geometric algebra‐based variation of a well‐known threshold secret‐sharing scheme introduced by Adi Shamir in 1979. Secret sharing is a cryptographic primitive which allows a secret input to be divided into multiple shares which are then sent to a collection of parties. The shares are generated so that only “authorized” sets of shares can reconstruct the secret. In Shamir's scheme, any sufficiently large set of shares can reconstruct the secret. The minimum number of shares which can obtain the secret is called the threshold, and any number of shares smaller than the threshold reveals nothing about the secret. The shares are generated such that each party can perform computations, generating a new set of shares that, when reconstructed, are equivalent to performing those exact computations directly on the secret input data. Our variant changes the domain from which secrets are taken: A finite field with prime order is replaced by a geometric algebra over a finite field of prime order. This change preserves the important security properties of Shamir's scheme, namely, idealness (secrets and shares are chosen from the same space) and perfectness (“unauthorized” sets of shares learn nothing about the secret). Our scheme allows secret sharing to be seamlessly added to the arsenal of GA‐based applications. Our extension of Shamir's secret scheme was first worked out for geometric algebras. It appears, however, that in fact it works for other algebras, a situation worthy to be explored in future work. For definiteness, in this paper, we restrict the analysis to the case of geometric algebras.

Towards Fully Anonymous Integrity Checking and Reliability Authentication for Cloud Data Sharing

Cloud storage services improve the efficiency and popularity of data sharing. These services allow groups of participants to jointly maintain the shared data. As important security properties of cloud data sharing, the integrity and the reliability of the shared data have been studied recently. However, the existing research cannot sufficiently solve the issue of participant identity anonymity in the scenario of data modification. In this paper, we propose a novel approach to achieve fully anonymous integrity checking and reliability authentication for cloud data sharing. We design a predicate for the shared data, and construct the Lagrange interpolation polynomials for all participants to compute the secret keys based on the designed predicate. When modifying the shared data, the participants compute the authenticators of the modified data using the secret key associated with the designed predicate instead of their identities. In this way, the integrity checking and reliability authentication of the shared data modified by different participants can be performed while the identities of the corresponding participants remain fully anonymous. In addition, the traceability and revocation of participant identity are considered. The performance analysis demonstrates the efficiency of the proposed approach, and the security analysis shows that the proposed approach satisfies the desired properties.

A lightweight encryption and message authentication framework for wireless communication

Confidentiality and authentication are two important security properties of wireless communication. There are currently two types of research in wireless communication security: one is based on cryptography, which can be too complicated for some wireless systems; the other is based on physical layer characteristics, which has some security problems and cannot work as well as the cryptography-based method. In this paper, a lightweight encryption and message authentication framework for wireless communication is proposed. The proposed framework has lower complexity than the cryptography-based method and works more securely and efficiently than the classical physical layer method. For the encryption, a physical layer offered chain key (PHYLOCK) structure is proposed to generate one-time keys, which are then XOR-ed with the plaintext to generate the ciphertext. A security analysis of PHYLOCK is performed and it is proved that it has better security features than the traditional physical layer key generation. For the message authentication, three types of PHYLOCK-CRC-based message authentication schemes are developed whose generator polynomial is determined by one-time keys generated by PHYLOCK. PHYLOCK-CRC-based message authentication detects not only random errors introduced by noises but also malicious attacks. The error-detecting and anti-attack capabilities are analyzed mathematically. Compared to the standard CRC, PHYLOCK-CRC-based message authentication has a decline in error correction capability but is enhanced with cryptographic security features. Monte-Carlo simulations are provided to evaluate the proposed scheme.

Privacy-Preserving Reputation Systems Based on Blockchain and Other Cryptographic Building Blocks: A Survey

The purpose of a reputation system is to hold the users of a distributed application accountable for their behavior. The reputation of a user is computed as an aggregate of the feedback provided by fellow users in the system. Truthful feedback is clearly a prerequisite for computing a reputation score that accurately represents the behavior of a user. However, it has been observed that users can hesitate in providing truthful feedback because, for example, of fear of retaliation. Privacy-preserving reputation systems enable users to provide feedback in a private and thus uninhibited manner. In this survey, we propose analysis frameworks for privacy-preserving reputation systems. We use these analysis frameworks to review and compare the existing approaches. Emphasis is placed on blockchain-based systems as they are a recent significant development in the area. Blockchain-based privacy-preserving reputation systems have properties, such as trustlessness, transparency, and immutability, which prior systems do not have. Our analysis provides several insights and directions for future research. These include leveraging blockchain to its full potential in order to develop truly trustless systems, to achieve some important security properties, and to include defenses against common attacks that have so far not been addressed by most current systems.

Enhanced Inf-TESLA Protocol: A Continuous Connectivity and Low Overhead Authentication Protocol via IoT Devices

Continuous and low-cost broadcast authentication is a fundamental security service for distributed sensor networks. This paper presents a novel development of a continuous and low-overhead broadcast authentication protocol named enhanced Infinite timed-efficient stream-loss tolerant authentication (enhanced Inf-TESLA) protocol, based on the Inf-TESLA protocol, whose continuous authentication is limited to the duration of its keychains. The enhanced Inf-TESLA protocol satisfies important security properties, including lower communication and computational overhead; a continuous generation of keychains without the need to establish synchronization packets; scalability to a large network; and resistance to masquerading, modification, man-in-the-middle, and replay attacks. We also highlighted an unaddressed authentication issue in the last packets of the original TESLA protocol and proposed a corresponding solution. We performed a simulation analysis using JAVA and proved that, compared to the Inf-TESLA protocol, the enhanced Inf-TESLA protocol can continuously authenticate packets for the entire lifetime of the receiver. We also compared the enhanced Inf-TESLA protocol with the original TESLA protocol in terms of time complexity and critical authentication processes. The results revealed the superiority of the enhanced Inf-TESLA protocol over the original TESLA protocol in terms of the message authentication code (MAC) value generation time and packet authentication time, which we believe can significantly improve the lifetime and lower the energy expenditure of Internet of Things devices with limited power sources.

Towards fully verifiable forward secure privacy preserving keyword search for IoT outsourced data

As cloud computing and Internet of Things (IoT) are becoming more and more deeply integrated, the new secure challenge for IoT data has attracted great attention. Privacy preserving keyword search, as one important secure technique, achieves search over encrypted cloud-based IoT data. Forward security and verifiability are two important security properties for privacy preserving keyword search for cloud-based IoT data. Forward security makes privacy preserving keyword search schemes for cloud-based IoT data able to resist file injection attack, which is one new attack on privacy preserving keyword search when IoT data is updated. Verifiability makes privacy preserving keyword search schemes for cloud-based IoT data able to ensure the validity of the search results returned by cloud. However, to the best of our knowledge, all of existing privacy preserving keyword search schemes at most achieve forward security and partial verifiability. In order to solve this problem, we explore how to simultaneously achieve the forward security and the full verification for intelligent encrypted data processing in cloud-based IoT and propose the first fully verifiable forward secure privacy preserving keyword search scheme for IoT outsourced data. In order to achieve forward security, we construct the secure index based on the hash chain. In each update, the IoT data owner randomly chooses a string as a new state to generate the new trapdoor. The new trapdoor cannot match previous trapdoors. In order to achieve the full verifiability while still maintaining forward security for intelligent encrypted data processing in cloud-based IoT, we design novel authentication construction called Forward Secure Accumulative Authentication Tag (FSAAT). This kind of tag has the incremental property and supports the verification on the basis of efficient data update. We prove that our scheme is secure and efficient through detailed security analysis and experiments.

An Automatically Verified Prototype of the Tokeneer ID Station Specification

The Tokeneer project was an initiative set forth by the National Security Agency (NSA, USA) to be used as a demonstration that developing highly secure systems can be made by applying rigorous methods in a cost-effective manner. Altran UK was selected by NSA to carry out the development of the Tokeneer ID Station. The company wrote a Z specification later implemented in the SPARK Ada programming language, which was verified using the SPARK Examiner toolset. In this paper, we show that the Z specification can be readily and naturally encoded in the $$\{log\}$$ { l o g } set constraint language, thereby generating a functional prototype. Furthermore, we show that $$\{log\}$$ { l o g } ’s automated proving capabilities can discharge all the proof obligations concerning state invariants as well as important security properties. As a consequence, the prototype can be regarded as correct with respect to the verified properties. This provides empirical evidence that Z users can use $$\{log\}$$ { l o g } to generate correct prototypes from their Z specifications. In turn, these prototypes enable or simplify some verification activities discussed in the paper.

Lamred: Location-Aware and Privacy Preserving Multi-Layer Resource Discovery for IoT

The resources in the Internet of Things (IoT) network are distributed among different parts of the network. Considering huge number of IoT resources, the task of discovering them is challenging. While registering them in a centralized server such as a cloud data center is one possible solution, but due to billions of IoT resources and their limited computation power, the centralized approach leads to some efficiency and security issues. In this paper we proposed a location aware and decentralized multi layer model of resource discovery (LaMRD) in IoT. It allows a resource to be registered publicly or privately, and to be discovered in a decentralized scheme in the IoT network. LaMRD is based on structured peer-to-peer (p2p) scheme and follows the general system trend of fog computing. Our proposed model utilizes Distributed Hash Table (DHT) technology to create a p2p scheme of communication among fog nodes. The resources are registered in LaMRD based on their locations which results in a low added overhead in the registration and discovery processes. LaMRD generates a single overlay and it can be generated without specific organizing entity or location based devices. LaMRD guarantees some important security properties and it showed a lower latency comparing to the cloud based and decentralized resource discovery.

ARTINALI++: Multi-dimensional Specification Mining for Complex Cyber-Physical System Security

Cyber-Physical Systems (CPSes) have been investigated as a key area of research since they are the core of Internet of Things. CPSs integrate computing and communication with control and monitoring of entities in the physical world. Due to the tight coupling of cyber and physical domains, and to the possible catastrophic consequences of the malicious attacks on critical infrastructures, security is one of the key concerns. However, the exponential growth of IoT has led to deployment of CPSes without support for enforcing important security properties. Specification-based Intrusion Detection Systems (IDS) have been shown to be effective for securing these systems. Mining the specifications of CPSes by experts is a cumbersome and error-prone task. Therefore, it is essential to dynamically monitor the CPS to learn its common behaviors and formulate specifications for detecting malicious bugs and security attacks. Existing solutions for specification mining only combine data and events, but not time. However, time is a semantic property in CPS systems, and hence incorporating time in addition to data and events, is essential for obtaining high accuracy.This paper proposes ARTINALI++, which dynamically mines specifications in CPS systems with arbitrary size and complexity. ARTINALI++ captures the security properties by incorporating time as a substantial property of the system, and generate a multi-dimensional model for the general CPS systems. Moreover, it enhances the model through discovering invariants that represent the physical motions and distinct operational modes in complex CPS systems. We build Intrusion Detection Systems based on ARTINALI++ for three CPSes with various levels of complexity including smart meter, smart artificial pancreas and unmanned aerial vehicle, and measure their detection accuracy. We find that the ARTINALI++ significantly reduces the ratio of false positives and false negatives by 23.45% and 73.6% on average, respectively, over other dynamic specification mining tools on the three CPS platforms.

A Lightweight Three-Factor Anonymous Authentication Scheme With Privacy Protection for Personalized Healthcare Applications

Security and privacy issues in wireless medical sensor networks (WMSNs) have attracted lots of attention in both academia and industry due to the sensitiveness of medical system. In the past decade, extensive research has been carried out on these security issues, but no single study exists that addresses them adequately, especially for some important security properties, such as user anonymity and forward secrecy. As a step towards this direction, in this paper, the authors propose a lightweight three-factor anonymous authentication scheme with forward secrecy for personalized healthcare applications using only the lightweight cryptographic primitives. The proposed scheme adopts pseudonym identity technique to protect users' real identities and employs one-way hash chain technique to ensure forward secrecy. Analysis and comparison results demonstrate that the proposed scheme can not only reduce execution time by 34% as compared with the most effective related schemes, but also achieve more security and functional features.

Faster Authenticated Key Agreement With Perfect Forward Secrecy for Industrial Internet-of-Things

Industrial Internet-of-Things (IIoT) is the basis of Industry 4.0, which extends Internet connectivity beyond traditional computing devices like computers and smartphones to the physical world for improving efficiency and accuracy while reducing the production cost. However, there are tremendous security threats to IIoT, such as IIoT device hijacking and data leaks. Therefore, a lightweight authenticated key agreement (AKA) protocol is commonly applied to establish a session key for securing the communication between IIoT devices. To protect the previous session keys from being compromised, perfect forward secrecy (PFS) has been one of the most important security properties of AKA. In this article, we present an efficient PFS-enabled AKA protocol for IIoT systems, which is developed based on a new dynamic authentication credential (DAC) framework, without using any public-key cryptographic primitives. It is worth noting that our protocol is also faster than the state-of-the-art DAC-based AKA protocols with PFS. Moreover, we give the formal security result of the proposed protocol in the random oracle model.

Towards more secure EMV purchase transactions

EMV is the protocol implemented to secure the communication, between a client’s payment device and a merchant’s payment device, during a contact or an NFC purchase transaction. It represents a set of security messages and rules, exchanged between the different transaction actors, guaranteeing several important security properties, such as authentication, non-repudiation and integrity. Indeed, researchers, in various studies, have analyzed the operation of this protocol in order to verify its safety: unfortunately, they have identified two security vulnerabilities that lead to multiple attacks and dangerous risks threatening both clients and merchants. In this paper, we are firstly interested in presenting a general overview of the EMV protocol and secondly, in proposing a new security solution that enhances the EMV protocol by solving the two dangerous EMV vulnerabilities. We verify the accuracy of our solution by using the Scyther security verification tool.

Opacity Measures of Fuzzy Discrete Event Systems

Opacity, as an important security property, has been well investigated in crisp discrete event systems. However, in some practical systems, the general behaviors, secret and nonsecret behaviors obtained by the intruder need to be expressed as fuzzy sets rather than crisp sets. Under this situation, the intruder makes inferences by fuzzy logic rather than classic logic, thus the notions of the fuzzy opacity measures are desired to be established. First, by means of the basic laws of fuzzy logic, a general fuzzy opacity measure, as a template, is presented, in this article, for the given generalized characterizations of secret and nonsecret behaviors. Moreover, a specific measure, called as fuzzy initial-final opacity (FIFO) measure, is investigated under the assumption that the secrets and nonsecrets can be coded into the initial-final state-pairs. In addition, two variants of FIFO measure are also proposed under the assumptions that the secrets and nonsecrets are only related to the initial-states or final-states. With these fuzzy opacity measures, the system designers can evaluate the opacity degree of the systems to be designed. To show the applicability of the fuzzy opacity measures to practical systems, we finally present an illustrative example of evaluating the location privacy protection systems in location-based services by means of the fuzzy opacity measures.

Privacy Preserving Visual Log Service with Temporal Interval Query using Interval Tree-based Searchable Symmetric Encryption

Visual logs become widely available via personal cameras, visual sensors in smart environments, or surveillance systems. Storing such data in public services is a common convenient solution, but it is essential to devise a mechanism to encrypt such data to protect sensitive information while enabling the capability to query visual content even in encrypted format at the services. More precisely, we need smart systems that their security and practicality must be balanced against each other. As far as we know, in spite of their importance in preserving personal privacy, such reliable systems have not gained sufficient attention from researchers. This motivates our proposal to develop a smart secure service for visual logs with a temporal interval query. In our system, visual log data are analyzed to generate high-level contents, including entities, scenes, and activities happening in visual data. Then our system supports data owners to query these high-level contents from their visual logs at the server-side in a temporal interval while the data are still encrypted. Our searchable symmetric encryption scheme TIQSSE utilizes interval tree structure and we prove that our scheme achieves efficient search and update time while also maintaining all important security properties such as forward privacy, backward privacy, and it does not leak information outside the desired temporal range.

FTGPHA: Fixed-Trajectory Group Pre-Handover Authentication Mechanism for Mobile Relays in 5G High-Speed Rail Networks

For high-speed rail networks, data transmission suffers from severe penetration loss and when the train moves from one base station to another, a large number of User Equipments (UEs) on board carry out the handover authentication procedure simultaneously, which incurs a lot of handover overheads. The introduction of Mobile Relay Node (MRN) can improve the link quality and decrease the handover overheads. However, MRNs still suffer from several protocol attacks and frequent handovers and thus, the introduction of MRNs deteriorates the handover success rate and handover performance. At the same time, considering the diversity of future 5G high-speed rail networks, in this paper, we propose two fixed-trajectory group pre-handover authentication schemes for MRN: the first proposed scheme FTGPHA1 which establishes most of the important security properties and costs low handover overheads, and the second proposed scheme FTGPHA2 which furnishes better security properties than the first one. In these two schemes, since all of the MRNs in the same train and the next base station can accomplish the handover authentication with the help of the donor software defined networking controller before the MRN arrives, the handover delay can be ignored and thus, uninterrupted services can be provided for UEs on board. The security and performance evaluations demonstrate that the two proposed schemes outperform other related schemes.

Dynamic Group-Oriented Provable Data Possession in the Cloud

As an important security property of cloud storage, data integrity has not been sufficiently studied under the multi-writer model, where a group of users work on shared files collaboratively and any group member can update the data by modification, insertion, and deletion operations. Existing works under such multi-writer model would bring large storage cost to the third-party verifiers. Furthermore, to the best of our knowledge, none of the existing works for shared files supports fully dynamic operations, which implies that users cannot freely perform the update operations. In this paper, we propose the first public auditing scheme for shared data that supports fully dynamic operations and achieves constant storage cost for the verifiers. Our scheme, named PRAYS, is boosted by a new paradigm for remote data integrity checking. To implement the new paradigm, we proposed a specially designed authenticated structure, called blockless Merkle tree, and a novel cryptographic primitive, called permission-based signature. Extensive evaluation demonstrates that PRAYS is as efficient as the existing less-functional solutions. We believe that PRAYS is an important step towards designing practical multi-writer cloud storage systems.

Lightweight Authentication and Key Agreement for Smart Metering in Smart Energy Networks

Smart meters (SMs) are considered as foundational part of the smart metering infrastructure (SMI) in smart energy networks (SENs). SM is a digital device that makes use of two-way communication between consumer and utility to exchange, manage and control energy consumptions within a home. However, despite all the features, an SM raises several security-related concerns. For instance, how to exchange data between the legal entities (e.g., SM and utility server) while maintaining privacy of the consumer. To address these concerns, authentication and key agreement in SMI can provide important security properties that not only to maintain a trust between the legitimate entities but also to satisfy other security services. This work presents a lightweight authentication and key agreement that enables trust, anonymity, integrity and adequate security in the domain of SEN. The proposed scheme employs hybrid cryptography to facilitate mutual trust (authentication), dynamic session key, integrity, and anonymity. We justify the feasibility of the proposed scheme with a test-bed using 802.15.4 based device (i.e., SM). Moreover, through the security and performance analysis, we show that the proposed scheme is more effective and energy efficient compared to the previous schemes.

Theorem proof based gate level information flow tracking for hardware security verification

Digital hardware lies in the heart of systems deployed in finance, medical care, basic infrastructure and national defense systems. However, due to the lack of effective security verification tools, hardware designs may contain security vulnerabilities resulting from performance optimizations, side channels, insecure debug ports and hardware Trojans, which provide attackers low level access to critical resources and effective attack surface to compromise a system. To address these security threats, we propose a theorem proof based gate level information flow tracking (GLIFT) method for formal verification of security properties and identifying security vulnerabilities that cause security property violations. Our method integrates a precise information flow tracking (IFT) model with the Coq theorem proof environment, inheriting the accuracy of GLIFT and the scalability of theorem proving based formal verification. We formalize semantic circuits and security theorems for proving security properties in order to detect security violations. The proposed method has been demonstrated on an OpenRISC development interface core and an RSA implementation both from OpenCores as well as several Trojan benchmarks from Trust-HUB. Experimental results show that the proposed method detects insecure debug port, timing channel and hardware Trojans that cause violation of important security properties such as confidentiality, integrity and isolation and also derives the trigger condition of hardware Trojans.

Anonymous certificate-based broadcast encryption with constant decryption cost

Most of the existing broadcast encryption schemes are constructed in either public key cryptosystem or identity-based cryptosystem. However, the overload of certificate management is heavy for public key cryptosystem while the key escrow problem is inherent in identity-based cryptosystem. Certificate-based cryptosystem provides a promising solution of designing more efficient and secure broadcast encryption schemes. Meanwhile, it is an important security property to protect the privacy of receivers, anonymity in many broadcast encryption application scenarios. Furthermore, in the broadcast encryption applications with a large number of computationally constrained users, it is critical to lower the computation cost, especially the decryption cost of the users. In this paper, we first introduce the notion of anonymous certificate-based broadcast encryption. Specifically, we formalize the definition and security model for anonymous certificate-based broadcast encryption. Then we construct an anonymous certificate-based broadcast encryption scheme with constant decryption cost. Compared with the existing anonymous multi-receiver certificate-based encryption scheme, the proposed scheme has advantage in the computation efficiency. Therefore, our scheme is more feasible for those broadcast encryption application scenarios where there are many receivers with limited computation ability. In the respect of security, the proposed scheme achieves anonymity and confidentiality against adaptive chosen-ciphertext attacks simultaneously under standard assumption.