Most of the cryptographic protocols currently in use are not appropriate for Internet of Things (IoT) environments because of their huge computing overhead, especially for terminal-embedded devices with resource constrained. Moreover, the computing resources in IoT environments are frequently asymmetric, that is to say, the computing power of the terminal devices is always weak and the server side is relatively stronger. In order to guarantee the security in the scenario, we present the asymmetric computing cryptosystem. Take the key exchange protocol as an example, we show how to construct ACKE, an asymmetric computing key exchange protocol, by employing the Diffie–Hellman key exchange protocol and the Subset Product problem (NP-complete) in this article. The underlying idea this construction is to significantly decrease the computational complexity of one party, and allow for a suitable rise in the computational complexity of another party. Our proposed protocol is implemented on an IoT simulation platform composed of a notebook PC of Intel i5-5200U 2.2 GHz/8G and a smart watch of MTK6062 1.2 GHz/512M. The experimental results show that this work will assist in making the Diffie–Hellman type protocol suitable for practical applications in IoT environments.

Healthcare cyber-physical system significantly facilitates healthcare services and patient treatment effectiveness by analyzing patients’ health information data conveniently. Nevertheless, it also develops the threats to the confidentiality of health information, patients’ privacy, and decidability of medical disputes. And, with the advances of quantum computing technology, most existing anonymous authentication schemes are becoming a growing threat to traditional cryptosystems. To address these problems, for healthcare cyber-physical systems, we propose a new lattice-based self-enhancement authorized accessible privacy authentication scheme by using a strong designated verifier double-authentication-preventing signature technique, called SEAPA. The SEAPA achieves three security and privacy requirements including unforgeability, anonymity for patients’ information, and self-enhancement for patients themselves. A detailed security proof shows our proposal achieves those required security goals. Finally, our construction is demonstrated by parameter analysis and performance evaluation to have reasonable efficiency.

Consortium blockchain has been widely used in different scenarios, where blockchain members demand that their uploaded data could be audited under their identities without exposing the data themselves. However, so far, no solution of privacy-preserving data auditing has been proposed. To address the problem, we propose zkrpChain, which focuses on protection of the integrity and privacy of the data uploaded by blockchain members while leaving their identities public. In zkrpChain, which is based on Hyperledger Fabric and Bulletproofs, both standard-range and arbitrary-range zero-knowledge range proofs generation and verification are supported. To improve the efficiency, the aggregation of multiple proofs and batch verification are also developed. For further development, we provide the client codes, chaincodes and related APIs. Finally, we conduct experiments to evaluate the performance of zkrpChaln, and the results show that the consumed time (in an 8-thread scheme) of chaincodes and needed on-chain space of zkrpChain are very close to Bulletproofs, which is evaluated in a single-machine environment.

Secure masking schemes have been proven in theory to be secure countermeasures against side-channel attacks. The security framework proposed by Ishai, Sahai and Wagner, known as the Ishai-Sahai-Wagner scheme, is one of the most acceptable secure models of the existing dth-order masking schemes, where d represents the masking order and plays the role of a security parameter. However, a gap may exist between scheme and design. Several analyses have determined that the glitch has been regarded as the main challenge of masking in hardware designs. A practical method of locating the precise position of leakage points (LPs) in the original hardware design is very rare. Existing research on this glitch mainly focuses on the first-order leakages; however, higher-order analysis can combine several shares to recover the secret key. In this paper, we propose a practical method, sensitive glitch location (SGL) method to locate the less order leakage in hardware design. Specifically, the SGL method can locate any-order of LP in the hardware implementation of dth-order masking schemes. We conducted experiments and verified that the time complexity of SGL on the dth-order masking schemes is O(nm), where m is the number of signals and n is the number of shares in masking scheme. It can therefore be regarded as an efficient tool for the masking designs. In addition, we analyzed the dth-order masking scheme proposed by Rivain and Prouff (2010) along with the SecMult algorithm from the Rivain-Prouff countermeasure, which has been analyzed by our SGL. The experimental results verified that a higher-order leakage may exist in certain hardware designs, even the masking scheme has been proven as a secure countermeasure. To the best of our knowledge, SGL is the first tool that can be used to locate any-order of power/electromagnetic LP in hardware designs. It thus shows the weakness in the original design file of hardware implementations. This property can help designers directly improve the real security of the designs. Moreover, SGL returns the path of the leakages, which can elucidate the original cause and propagation of the weakness.

Leakage models, regarded as a bridge between the physical signal and the sensitive operation, have a great influence on the effectiveness of the side channel analysis. The existing leakage models are usually divided into two categories, the non-profiled leakage models which have been chosen before sampling and analyzing, such as Hamming weight and Hamming distance, while the profiled leakage models, whose parameters have to be trained in the profiling phase, such as the Stochastic model of which both coefficient vector and pooled covariance matrix are required to be estimated based on the acquired samples. In general, a profiled leakage model is more accurate than a non-profiled one. However, it may lead to an inefficient attack if the leakage function is inaccurate, e.g., the over-fitting and under-fitting in the profiling phase. In this paper, we mathematically prove the relationship among different stochastic models, and propose a new method named ECM to solve the problem that much time is required to solve matrix in the profiling phase. Replacing the observations in the matrix solution with the average signals, the new method accelerates the construction of any stochastic model significantly, as long as the data-dependent signal has the property equal images under different subkeys. On the basis of theoretical results, we analyze the reasons why over-fitting and under-fitting happen, and quantify the condition when some of them occur. Finally, comparing with the existing construction method (HSS2012), we verify the effectiveness and efficiency of ECM with different metrics. Under the same accuracy, the ECM obviously has lower time complexity than HSS2012.

Moving target defense (MTD) has provided a dynamic and proactive network defense to reduce or move the attack surface that is available for exploitation. However, traditional network is difficult to realize dynamic and active security defense effectively and comprehensively. Software-defined networking (SDN) points out a brand-new path for building dynamic and proactive defense system. In this paper, we propose CHAOS, an SDN-based MTD system. Utilizing the programmability and flexibility of SDN, CHAOS obfuscates the attack surface including host mutation obfuscation, ports obfuscation, and obfuscation based on decoy servers, thereby enhancing the unpredictability of the networking environment. We propose the Chaos Tower Obfuscation (CTO) method, which uses the Chaos Tower Structure (CTS) to depict the hierarchy of all the hosts in an intranet and define expected connection and unexpected connection. Moreover, we develop fast CTO algorithms to achieve a different degree of obfuscation for the hosts in each layer. We design and implement CHAOS as an application of SDN controller. Our approach makes it very easy to realize moving target defense in networks. Our experimental results show that a network protected by CHAOS is capable of decreasing the percentage of information disclosure effectively to guarantee the normal flow of traffic.

The security analysis of protocols on theory level cannot guarantee the security of protocol implementations. To solve this problem, researchers have done a lot, and many achievements have been reached in this field, such as model extraction and code generation. However, the existing methods do not take the security of protocol implementations into account. In this paper, we have proposed to exploit the traces of function return values to analyze the security of protocol implementations at the source code level. Taking classic protocols into consideration, for example (like the Needham-Schroeder protocol and the Diffie-Hellman protocol, which cannot resist man-in-the-middle attacks), we have analyzed man-in-the-middle attacks during the protocol implementations and have carried out experiments. It has been shown in the experiments that our new method works well. Different from other methods of analyzing the security of protocol implementations in the literatures, our new method can avoid some flaws of program languages (like C language memory access, pointer analysis, etc.) and dynamically analyze the security of protocol implementations.

Eight years ago, Pei et al . described a matrix public‐key encryption scheme based on the matrix factorisation over a finite field. Recently, Gu and Zheng also proposed a similar scheme based on the non‐abelian factorisation assumption. The security of these schemes is essentially based on a two‐side matrices exponentiation (TSME) problem. In this study, the authors show that the TSME problem is susceptible to a very efficient linearisation equations attack. Regardless of the public key parameters, the authors can easily find an equivalent key only in polynomial time 𝒪(2 n 5 (log n +1)) from the public key alone, and thus it is very practical and can be implemented within less than 1/20 of a second on the recommended system parameters of the schemes.

Abstract Opportunistic vehicular ad hoc networks have attracted enormous attention from both industry and academia in recent years. However, the presence of selfish behaviors of nodes could cause a severe threat to well designed opportunistic routing scheme, and even jeopardize the whole network. This paper presents a privacy‐preserving distance‐based incentive scheme, particularly to address issues of the nodes' selfish behavior and the location privacy. The proposed protocol adopts secure multiparty computation and homomorphic encryption methods to realize three properties, i.e., the confidentiality of nodes location information, the integrity of the message carried distance, and the correctness of reputation computation. Furthermore, this incentive scheme can satisfy the following security requirements, such as mutual authentication, non‐repudiation, and conditional privacy preservation, and it can also stimulate the active helpers and suppress harmful behaviors fairly and reasonably. The security analysis and performance evaluation show that the proposed framework is secure, efficient, and practical. Copyright © 2015 John Wiley & Sons, Ltd.

Abstract Trusted Platform Module (TPM) is the “root of trust” of the whole trusted computing platform. The TPM's own security assurance is very important. This paper describes the TPM 2.0 hash‐based message authentication code (HMAC) authorization scheme as a security protocol and makes a detail comparison of the TPM 2.0 authorization to the TPM 1.2 “Object‐Independent Authorization Protocol” and the “Object‐Specific Authorization Protocol.” Then the authors use the typed pi calculus to describe the TPM 2.0 HMAC authorization and its security properties under the Digital Rights Management (DRM) scenario and use ProVerify to reason that the key handle manipulation attack for TPM 1.2 does not exist any more in TPM 2.0, because the access entity unique name has been linked to the HMAC value, but the vulnerability of key blob substitution still exists in TPM 2.0. Copyright © 2015 John Wiley & Sons, Ltd.

In this paper, a framework of end to end (E2E) trusted cloud infrastructure is proposed. On one end of the cloud provider, the trusted chain is extended to VMM and VM by trusted measurement and remote attestation, which can assure the trust of VMM and VM. On another end of the cloud terminal, the trusted mechanism is used to protect the terminal security. For the trust of cloud network, trusted network connect (TNC) is leveraged to protect the security of communication between the loud provider and the cloud terminal. The E2E trusted cloud infrastructure provides an E2E trusted protection for cloud computing. In addition, it can support the Chinese cryptographic algorithm (SMx) based on TPM 2.0.

SUMMARY The recent cryptanalysis on block ciphers has two major trends. Side channel analysis (SCA) has become a new threat to the hardware implementations of encryption algorithms. On the other hand, reverse engineering has been adopted to explore the unknown part of the encryption algorithms, which has become a new target of the cryptanalysis. Some drawbacks have been found in the existing methods of reverse engineering, which target on the special structures or utilize the flaws in the unknown parts. The major disadvantage is that the number of rounds to be analyzed is limited, and the complexity is high. The existing SCAs for reverse engineering depend on the leakage models in a large extent and mainly focus on the single component of the algorithms, whereas the other parts of the target algorithm are known. In this paper, we present a more general and feasible reverse analysis by combining the mathematical methods and the SCA methods. We use the strict avalanche criterion for the non‐linear operations of block ciphers and apply the power analysis to reverse the structure parameters. We propose a new reverse analysis method to reduce the dependency on the leakage models, which can be combined with the structural cryptanalysis to reverse the internal parameters of the linear and non‐linear operations. We finally achieve the reverse analysis on the unknown round function of block ciphers. Copyright © 2013 John Wiley & Sons, Ltd.

This paper presents a testing method of code redundancy simplification from the aspect of software static analysis. We study on the dependency relationships between the variables, branches and functions in source or intermediate code of the tested object by PDG (Program Dependence Graph). This method establishes an effective testing to discover and locate the redundant functional modules and the unreachable paths based on dependency relationship. Compared with the conventional code optimization which emphasizes the improvement of time efficiency, we compress the size of source code and object code, independent of the programming language the source program uses. Experimental results show that the source or object code size decreases by 1 to 3 percent approximately after our simplification, not only reducing the occupied space but also assuring the functional consistency.

Key agreement is one of the fundamental cryptographic primitives in public key cryptography. It plays an important role for securing systems in practice. In this paper, we present the first certificateless one-way authenticated two-party key agreement protocol. The security of the proposed protocol is analyzed based on the intractability of the standard discrete logarithm (DL) and bilinear Diffie-Hellman (BDH) problems. For efficiency, our protocol enjoys low complexity in both communication and computation.

Security of computer architecture is basis of trusted system. For the sake of compromising to commerce,trusted computing platform's product is really not the best secure architecture. It is short of supporting trust spread because of chain trust relationship. So we put forward a specific trust model, and then advance a secure and reconfigurable architecture distinguishing from traditional architectures. The model can give prominence to trusted root and reduce the loss of trust after trust chain had transferred. We also design out new architecture according to our model. The prototype system validates that new architecture can effectively resolve trust expansion.

Secure bootstrap usually use integrity measurement scheme to verify code or data before they are loaded into memory. As to traditional PC (personal computer) architecture, this method is hard to protect security of system software and application especially.This paper researches the different components running on system and divides them into two kind TCB (trusted computing base), i.e. HTCB (hardwareTCB) and STCB (software TCB). Combing with technologies such as VM (virtual machine), integrity measurement and sealed storage, prototype lets STCB bind with HTCB so that trusted chain can be extended from hardware layer to system software layer. Lastly,detailed implement ways and means for prototype are given.

Based on the trace representation of Boolean functions, we devise an evolutionary algorithm to design bent functions. Using this algorithm, we then construct many bent functions and perform some analyses. First, we observe that each of the four affinely inequivalent bent functions in six variables can be written as the linear sum of two or three monomial trace functions. We draw the conclusion that the affine transformation can be used to change the linear span of the Boolean functions and thereby change the trace representation of our obtained bent functions. Second, we find that certain exponents are more suitable for constructing bent functions than others. From this observation, we assign each exponent a cost function, which makes our algorithm more efficient than an exhaustive search algorithm or a random algorithm. Third, we classify the obtained bent functions into affinely inequivalent classes, and the number of classes is presented.

Trust model is an effort to guarantee secure and high quality interactions in P2P(peer-to-peer) file sharing systems. Traditional trust models always depend on past performance quantified in term of reputation or recommendation. This paper presents PerformTrust -a history and current performance based trust supporting framework which includes an intensive trust model for offering trustworthiness of peers quantitatively and comparatively based on a history performance feedback system and a current performance evaluating system with a decentralized implementation over a structured P2P network. PerformTrust has two main features. First, we introduce a virtual domain in every peer that would take responsible of collecting information about current performance of peers, including files integrity and peers response time. Second, PerformTrust considers both history and current performance of a peer for evaluating trustworthiness. Other contributions include adjustment scenario of the trust model, and a set of experiment that show the effectiveness and benefit of our approach.

With advances in hardware-assisted full virtualization technologies, system virtualization based on the virtual machine monitor (VMM) has received much recent attention. Using the Xen/IA64 hardware virtual machine implemented on Intel® Virtualization Technology for Itanium® (VT-i), we investigate the design of a virtual software hash translation lookaside buffer (TLB) based on the virtual hash page table (VHPT). Experimental results show that the proposed design can significantly improve the performance of the hardware virtual machine of Xen/IA64. Our contributions are the following. First, we design and implement in the VMM a virtual hash TLB algorithm to optimize the system performance of VT-i guest virtual machines. Second, we quantify experimentally the performance benefits of the hash TLB for VT-i guest virtual machines and analyze the performance impact of the software VHPT walker with the hash TLB algorithm. Lastly, we present experiments to verify, in an SMP virtual machine system environment, the superior scalability of the hash TLB approach.

Accountability is a key property in electronic transaction. In the past a few years a lot of work on accountability have done. But these work mainly only focus on the field of electronic commerce, at the same time the logics introduced before, such as Herreweghen' logic, Kailar' logic, Kessler&Neumann' logic and Kungpisdan&Permpoontanalarp' logic, used in analysis of the accountability is difficult for people in practice. In this paper, we introduce generally formal definition of accountability in electronic transaction. At the same time applying the generally formal definition we give the conditions of money accountability and goods accountability in the electronic payment protocol. According to the conditions we can easily judge whether the electronic payment protocols have the goods accountability and money accountability or not without complex analyses and logic reasoning.