Economical multiparty simultaneous quantum identity authentication based on Greenberger-Horne-Zeilinger states

A multiparty simultaneous quantum identity authentication protocol based on Creenberger-Horne-Zeilinger （GHZ） states is proposed. The multi-user can be authenticated by a trusted third party （TTP） simultaneously. Compared with the scheme proposed recently （Wang et al 2006 Chin. Phys. Lett. 23（9） 2360）, the proposed scheme has the advantages of consuming fewer quantum and classical resources and lessening the difficulty and intensity of necessary operations.

Comparative Evaluation of Elliptic Curve Cryptography Based Homomorphic Encryption Schemes for a Novel Secure Multiparty Computation

In this paper, we focus on Elliptic Curve Cryptography based approach for Secure Multiparty Computation (SMC) problem. Widespread proliferation of data and the growth of communication technologies have enabled collaborative computations among parties in distributed scenario. Preserving privacy of data owned by parties is crucial in such scenarios. Classical approach to SMC is to perform computation using Trusted Third Party (TTP). However, in practical scenario, TTPs are hard to achieve and it is imperative to eliminate TTP in SMC. In addition, existing solutions proposed for SMC use classical homomorphic encryption schemes such as RSA and Paillier. Due to the higher cost incurred by such cryptosystems, the resultant SMC protocols are not scalable. We propose Elliptic Curve Cryptography (ECC) based approach for SMC that is scalable in terms of computational and communication cost and avoids TTP. In literature, there do exist various ECC based homomorphic schemes and it is imperative to investigate and analyze these schemes in order to select the suitable for a given application. In this paper, we empirically analyze various ECC based homomorphic encryption schemes based on performance metrics such as computational cost and communication cost. We recommend an efficient algorithm amongst several selected ones, that offers security with lesser overheads and can be applied in any application demanding privacy.

An Efficient Multiparty Quantum-State Sharing Scheme

An efficient multipaxty quantum secret sharing scheme is proposed, in which the secret is a quantum state, and the dealer encodes the secret by performing the operations of quantum-controlled-not and Hadamard gate. The participants perform the single-particle measurements on their particles, and then can cooperate to recover the original quantum state. In our scheme, both the dealer and the participants do not need to perform the entanglement measurement. Compared with the existing schemes, our scheme is simpler and more efficient.

A Secure Multiparty Quantum Homomorphic Encryption Scheme

The significant advantage of the quantum homomorphic encryption scheme is to ensure the perfect security of quantum private data.In this paper,a novel secure multiparty quantum homomorphic encryption scheme is proposed,which can complete arbitrary quantum computation on the private data of multiple clients without decryption by an almost dishonest server.Firstly,each client obtains a secure encryption key through the measurement device independent quantum key distribution protocol and encrypts the private data by using the encryption operator and key.Secondly,with the help of the almost dishonest server,the non-maximally entangled states are preshared between the client and the server to correct errors in the homomorphic evaluation of T gates,so as to realize universal quantum circuit evaluation on encrypted data.Thirdly,from the perspective of the application scenario of secure multi-party computation,this work is based on the probabilistic quantum homomorphic encryption scheme,allowing multiple parties to delegate the server to perform the secure homomorphic evaluation.The operation and the permission to access the data performed by the client and the server are clearly pointed out.Finally,a concrete security analysis shows that the proposed multiparty quantum homomorphic encryption scheme can securely resist outside and inside attacks.

A Chinese Solution Multiparty cooperation and political consultation provide a new way to view democracy

On March 4, President Xi Jinping, also General Secretary of the Communist Party of China （CPC） Central Committee, attended a joint panel discussion with political advisors from the China Democratic League and the China Zhi Gong Party, those without party affiliation and those from the sector of returned over seas Chinese.

Multiparty semiquantum key agreement without entanglement

The key agreement protocols allow two or more users to negotiate a shared key for establishing a secure communication channel without a third trusted party in such a way that the shared key is determined by all authorized players rather than any subset of them.We propose the first real multiparty semiquantum key agreement(SQKA)protocols based on single-photons.Our protocols include only one quantum player,while the others are classical players who only need to measure and prepare states in the classical basis.We first present a symmetric three-party SQKA protocol,where two classical players can fairly negotiate a key with a quantum player by using single-photons as message carriers.Then we present an asymmetric SQKA protocol where a relatively low percentage of quantum states are used for eavesdropping detection.And we further extend them to an asymmetric multiparty SQKA protocol.Our SQKA protocols require fewer quantum resources than the previous SQKA protocols for classical players,especially without requirement of entanglement,which makes them easier to implement using current technologies.Our protocols are secure against external eavesdroppers and are fair against a minority of internal dishonest players.

Sender-controlled measurement-device-independent multiparty quantum communication

Multiparty quantum communication is an important branch of quantum networks.It enables private information transmission with information-theoretic security among legitimate parties.We propose a sender-controlled measurement-device-independent multiparty quantum communication protocol.The sender Alice divides a private message into several parts and delivers them to different receivers for secret sharing with imperfect measurement devices and untrusted ancillary nodes.Furthermore,Alice acts as an active controller and checks the security of quantum channels and the reliability of each receiver before she encodes her private message for secret sharing,which makes the protocol convenient for multiparity quantum communication.

Correlated Differential Privacy of Multiparty Data Release in Machine Learning

Differential privacy(DP)is widely employed for the private data release in the single-party scenario.Data utility could be degraded with noise generated by ubiquitous data correlation,and it is often addressed by sensitivity reduction with correlation analysis.However,increasing multiparty data release applications present new challenges for existing methods.In this paper,we propose a novel correlated differential privacy of the multiparty data release(MP-CRDP).It effectively reduces the merged dataset's dimensionality and correlated sensitivity in two steps to optimize the utility.We also propose a multiparty correlation analysis technique.Based on the prior knowledge of multiparty data,a more reasonable and rigorous standard is designed to measure the correlated degree,reducing correlated sensitivity,and thus improve the data utility.Moreover,by adding noise to the weights of machine learning algorithms and query noise to the release data,MP-CRDP provides the release technology for both low-noise private data and private machine learning algorithms.Comprehensive experiments demonstrate the effectiveness and practicability of the proposed method on the utilized Adult and Breast Cancer datasets.

Robust Threshold Guillou-Quisquater Signature Scheme

The deficiencies of the first threshold Guilbu-Quisquater signature schemepresented by Li-San Liu, Cheng-Kang Chu and Wen-Guey Tzeng arc analysiscd at first, and then a newthreshold Guillou-Quisquater signature scheme is presented. The new scheme isunforgeable and robustagainst any adaptive adversary if the base Guillou-Quisquater signature scheme is unforgeable underthe chosen message attack and computing the discrete logarithm modulo a prime is hard This schemecan also achieve optimal resilience. However, the new scheme does not need the assumption that N isthe product of two safe primes. The basie signature scheme underlying the new scheme is exactlyGuillou-Quisqualtr signature scheme, and the additional strong computation assumption introduced bythe first threshold Guillou-Quisquater scheme is weaken.

TWO PRIVACY-PRESERVING PROTOCOLS FOR POINT-CURVE RELATION

Numerous privacy-preserving issues have emerged along with the fast development of Internet, both in theory and in real-life applications. To settle the privacy-preserving problems, secure multi-party computation is essential and critical. In this paper, we have solved two problems regarding to how to determine the position relation between points and curves without revealing any private information. Two protocols have been proposed in order to solve the problems in different conditions. In addition, some building blocks have been developed, such as scalar product protocol, so that we can take advantage of them to settle the privacy-preserving computational geometry problems which are a kind of special secure multi-party computation problems. Moreover, oblivious transfer and power series expansion serve as significant parts in our protocols. Analyses and proofs have also been given to argue our conclusion.

Grand Multiparity: Obstetric Outcome in Comparison with Multiparous Women in a Developing Country

Grand-multiparity is a serious risk factor in pregnancy and common in developing countries. The objective was to compare the obstetric outcome of grand-multiparous women with that of low parity in our center. The study comprised of 150 grand-multiparous women (cases) and 150 multiparous women (para 2 - 4) in this index pregnancy as controls matched for age and admitted for delivery. The mean age of the grand-multiparous women at delivery was 37.0 ± 2.8 years. Grand-multiparity was significantly higher among women with only primary education (48.0% versus 44.7%), polygamous marriages (9.3% versus 3.3%) and Muslims (17.3% versus 6.7%). Pregnancy induced hypertension and primary postpartum hemorrhage were significantly more often seen among grand-multiparous women than among the controls. The mean packed cell volume before delivery in the grand-multiparous women was significantly lower (33.6% ± 2.7%) than in the multiparous group (35.2% ± 2.7%) (P-value = 0.000). Grand-multiparity with its associated complications still occurs frequently in our environment. However, with adequate antenatal surveillance, optimal care during labour and contraceptive use, these problems will be reduced.

Private Personal Information Verification

Physical document verification is a necessary task in the process of reviewing applications for a variety of services, such as loans, insurance, and mortgages. This process consumes a large amount of time, money, and human resources, which leads to limited business throughput. Furthermore, physical document verification poses a critical risk to clients’ personal information, as they are required to provide sensitive details and documents to verify their information. In this paper, we present a systematic approach to address shortcomings in the current state of the processes used for physical document verification. Our solution leverages a semi-trusted party data source (i.e. a governmental agency) and cryptographic protocols to provide a secure digital service. We make use of homomorphic encryption and secure multi-party computation to develop a series of protocols for private integer comparison and (non-) membership testing. Secure boolean evaluation and secure result aggregation schemes are proposed to combine the results of the evaluation of multiple predicates and produce the final outcome of the verification process. We also discuss possible improvements and other applications of the proposed secure system of protocols. Our framework not only provides a cost-efficient and secure solution for document verification, but also creates space for a new service.

Research on Privacy Preserving Data Mining

In recent years,with the explosive development in Internet,data storage and data processing technologies,privacy preservation has been one of the greater concerns in data mining.A number of methods and techniques have been developed for privacy preserving data mining.This paper provided a wide survey of different privacy preserving data mining algorithms and analyzed the representative techniques for privacy preservation.The existing problems and directions for future research are also discussed.

Quantum private query: A new kind of practical quantum cryptographic protocol

This research aims to review the developments in the field of quantum private query(QPQ), a type of practical quantum cryptographic protocol. The primary protocol, as proposed by Jacobi et al., and the improvements in the protocol are introduced.Then, the advancements made in sability, theoretical security, and practical security are summarized. Additionally, we describe two new results concerning QPQ security. We emphasize that a procedure to detect outside adversaries is necessary for QPQ, as well as for other quantum secure computation protocols, and then briefly propose such a strategy. Furthermore, we show that the shift-and-addition or low-shift-and-addition technique can be used to obtain a secure real-world implementation of QPQ, where a weak coherent source is used instead of an ideal single-photon source.

Symmetric cryptographic protocols for extended millionaires’ problem

Yao’s millionaires’ problem is a fundamental problem in secure multiparty computation, and its solutions have become building blocks of many secure multiparty computation solutions.Unfortunately, most protocols for millionaires’ problem are constructed based on public cryptography, and thus are inefficient.Furthermore, all protocols are designed to solve the basic millionaires’ problem, that is, to privately determine which of two natural numbers is greater.If the numbers are real, existing solutions do not directly work.These features limit the extensive application of the existing protocols.This study introduces and refines the first symmetric cryptographic protocol for the basic millionaires’ problem, and then extends the symmetric cryptographic protocol to privately determining which of two real numbers is greater, which are called the extended millionaires’ problem, and proposes corresponding protocols.We further prove, by a well accepted simulation paradigm, that these protocols are private.Constructed based on symmetric cryptography, these protocols are very efficient.

Distributed Oblivious Function Evaluation and Its Applications

This paper is about distributed oblivious function evaluation (DOFE). In this setting one party (Alice) has a functionf(x), and the other party (Bob) with an input α wants to learnf(α) in an oblivious way with the help of a set of servers. What Alice should do is to share her secret functionf(x) among the servers. Bob obtains what he should get by interacting with the servers. This paper proposes the model and security requirements for DOFE and analyzes three distributed oblivious polynomial evaluation protocols presented in the paper. Keywords oblivious function evaluation - oblivious polynomial evaluation - secure multiparty computation - distributed - information security The research is supported by the National Basic Research 973 Program of China under Grant No. 1999035802 and the National Natural Science Foundation of China under Grant No.60273029.Hong-Da Li was born in 1960. He received the Ph.D. degree from Northwestern Polytechnical University in 2001. His current research interests are cryptology and cryptographic protocol.Xiong Yang received the B.S. degree in mathematics from Yan'an University, China, in 1984. He is an associate professor in College of Economy and Trade at South China University of Tropical Agriculture. His research interest is information security.Deng-Guo Feng was born in 1963. He is now a Ph.D. supervisor. His research interests focus on information security.Bao Li was born in 1965. He received the Ph.D. degree in cryptography in 1995 from Xidian University. His research interests include cryptographic protocols and public key cryptosystems.

Aggregation Tree Statistical Computing Based on Functional Encryption

The medical monitoring system is widely used. In the medical monitoring system, each user only possesses one piece of data logging that participates in statistical computing. Specifically in such a situation, a feasible solution is to scatter its statistical computing workload to corresponding statistical nodes. Moreover, there are still two problems that should be resolved. One is how the server takes advantage of intermediate results obtained through statistical node aggregation to perform statistical computing. Statistical variable decomposition technique points out the direction for statistical projects. The other problem is how to design an efficient topological structure for statistical computing. In this paper, tree topology was adopted to implement data aggregation to improve aggregation efficiency. And two experiments were done for time consumption of statistical computing which focuses on encrypted data aggregation and encrypted data computing. The first experiment indicates that encrypted data aggregation efficiency of the scheme proposed in this paper is better than that of Drosatos' scheme, and the second indicates that improving computing power of the server or computational efficiency of the functional encryption scheme can shorten the computation time.

Comparing two sets without disclosing them

Secure multiparty computation has become a central research focus in the international cryptographic community. Secure comparing two sets is an important problem in secure multiparty computation. The research on privately determining whether two sets are equal has not been investigated. This study solves the problem by mapping these sets into natural numbers and then comparing correspond- ing numbers, We propose two secure multiparty computation protocols for comparing two sets. It is proved by well-accepted simulation paradigm that these solutions are private in semi-honest model. These solutions have important significance in constructing other secure multiparty computation protocols.

A Protocol for a Private Set-Operation

A new private set-operation problem is proposed. Suppose there are n parties with each owning a secret set. Let one of them, say P, be the leader, S be P＇s secret set, and t （less than n - 1） be a threshold value. For each element w of S, if w appears more than t times in the rest parties＇ sets, then P learns which parties＇ sets include w, otherwise P cannot know whether w appears in any party＇s set. For this problem, a secure protocol is proposed in the semi-honest model based on semantically secure homomorphic encryption scheme, secure sharing scheme, and the polynomial representation of sets. The protocol only needs constant rounds of communication.

Universal and General Quantum Simultaneous Secret Distribution with Dense Coding by Using One-Dimensional High-Level Cluster States

A universal and general quantum simultaneous secret distribution(QSSD)protocol is put forward based on the properties of the one-dimensional high-level cluster states,in which one sender dispatches different high-level classical secret messages to many users at the same time.Due to the idea of quantum dense coding,the sender can send different two-dit classical messages(two d-level classical numbers)to different receivers simultaneously by using a one-dimensional d-level cluster state,which means that the information capacity is up to the maximal.To estimate the security of quantum channels,a new eavesdropping check strategy is put forward.Meanwhile,a new attack model,the general individual attack is proposed and analyzed.It is shown that the new eavesdropping check strategy can effectively prevent the traditional attacks including the general individual attack.In addition,multiparty quantum secret report(MQSR,the same as quantum simultaneous secret submission(QSSS))in which different users submit their different messages to one user simultaneously can be gotten if the QSSD protocol is changed a little.