Device-independent quantum key distribution (DI-QKD) is a key application of the quantum internet. We report the realization of DI-QKD between two single-atom nodes linked by 100-kilometer (km) fibers. To improve the entangling rate, single-photon interference is leveraged for entanglement heralding, and quantum frequency conversion is used to reduce fiber loss. A tailored Rydberg-based emission scheme suppresses the photon recoil effect on the atom without introducing noise. We achieved high-fidelity atom-atom entanglement and positive asymptotic key rates for fiber lengths up to 100 km. At 11 km, 1.2 million heralded Bell pairs were prepared over 624 hours, yielding an estimated extractable finite-size secure key rate of 0.112 bits per event against general attacks. Our results close the gap between proof-of-principle quantum network experiments and real-world applications.

In the era of big data, traditional regression models cannot deal with uncertain big data efficiently and accurately. In order to make up for this deficiency, this paper proposes a quantum fuzzy regression model, which uses fuzzy theory to describe the uncertainty in big data sets and uses quantum computing to exponentially improve the efficiency of data set preprocessing and parameter estimation. In this paper, data envelopment analysis (DEA) is used to calculate the degree of importance of each data point. Mean-while, Harrow, Hassidim and Lloyd (HHL) algorithm and quantum swap circuits are used to improve the efficiency of high-dimensional data matrix calculation. The application of the quantum fuzzy regression model to small-scale financial data proves that its accuracy is greatly improved compared with the quantum regression model. Moreover, due to the introduction of quantum computing, the speed of dealing with high-dimensional data matrix has an exponential improvement compared with the fuzzy regression model. The quantum fuzzy regression model proposed in this paper combines the advantages of fuzzy theory and quantum computing which can efficiently calculate high-dimensional data matrix and complete parameter estimation using quantum computing while retaining the uncertainty in big data. Thus, it is a new model for efficient and accurate big data processing in uncertain environments.

With the development of information technology, modern society has entered the era of big data. Big data means a huge amount of data, as well as the complexity and uncertainty of data. In order to find valuable data efficiently and accurately from the big data environment, researchers use machine learning algorithms to establish relevant data models to predict and classify new data. In the process of establishing the linear system model, the commonly used method is the least square method, which can easily obtain the optimal parameters of the linear system and make the established linear model more accurate. In order to deal with the fuzziness of the data itself and reduce the influence of abnormal data on the linear model, researchers put forward the fuzzy linear model. When the amount of data is increasing, the time required for traditional computers to process data and establish models is increasing. In order to reduce the time of establishing the model, a quantum fuzzy least square method is proposed on the basis of predecessors. The algorithm uses the advantages of quantum computing in data processing to improve the efficiency of fuzzy linear model establishment and reduce the model establishment time. Relevant research and analysis prove the efficiency of the algorithm.

With the development and application of energy Internet technology, the collaborative interaction of "source network, load and storage" has become the development trend of power grid dispatching. The large-scale access of renewable energy on the load side, the unified management of adjustable loads, and the participation of multiple parties in energy operations have put forward requirements for the safety, credibility, openness, and transparency of the load dispatching environment. Under the environment of carbon emission reduction, the paper proposed an architecture of the scheduling data blockchain, based on the in-depth study of blockchain. Moreover, smart contracts are used to realize the application scenario of load dispatching instruction evidence on the blockchain. The content and storage mode of scheduling instruction evidence on blockchain are studied. And different storage modes are adopted according to the actual needs. And the smart contract system realizes the evidence generation of power dispatching instruction. This is the basis for the normal circulation of power dispatching instruction evidence. The research significance of this paper is highlighted as follows. The data and information generated in the power dispatching process are stored as evidence. On the one hand, it can provide a basis for settlement between power production and dispatching companies and power users. On the other hand, it can prepare for distributed transactions in the power grid under the environment of carbon emission reduction.

As a kind of distributed, decentralized and peer-to-peer transmittedtechnology, blockchain technology has gradually changed people's lifestyle.However, blockchain technology also faces many problems including selfishmining attack, which causes serious effects to the development of blockchaintechnology. Selfish mining is a kind of mining strategy where selfish minersincrease their profit by selectively publishing hidden blocks. This paper buildsthe selfish mining model from the perspective of node state conversion and utilizethe function extremum method tofigure out the optimal profit of this model.Meanwhile, based on the experimental data of honest mining, the author conductsthe simulation of selfish mining and discovers that selfish miners are able toacquire more revenue than honest miners when they account for more than1/3 computing power of the whole system. Lastly, to defend the selfish miningattack, the author also summarizes the existing defending strategies and evaluatesevery kind of strategy briefly.

Cerebral palsy is a group of persistent central movement and postural developmental disorders, and restricted activity syndromes. This syndrome is caused by non-progressive brain damage to the developing fetus or infants. Cerebral palsy assessment can determine whether the brain is behind or abnormal. If it exists, early intervention and rehabilitation can be carried out as soon as possible to restore brain function to the greatest extent. The direct external manifestation of cerebral palsy is abnormal gait. Accurately determining the muscle strength related reasons that cause this abnormal gait is the primary problem for treatment. In this paper, clustering methods were used to compare and analyze the differences between the abnormal and normal gait parameters of children with and without cerebral palsy. Since the collected data contains overlapping data that may be mutated, while the centroids are also different, the expected result is stratified. To solve this problem, a mixed clustering method is proposed that combines the advantages of K-means and hierarchical clustering, meaning that each set of data shows a similar trend to specific parameters. Experiment results show that this method can detect cerebral palsy through the difference between the abnormal gait of children with cerebral palsy and that of normal children.

During the current epidemic, it is necessary to ensure the rehabilitation treatment of children with serious illness. At the same time, however, it is essential to effectively prevent cross-infection and prevent infections from occurring within the hospital setting. To resolve this contradiction, the rehabilitation department of Nanjing Children's Hospital adjusted its bed allocation based on the queuing model, with reference to the regional source and classification of the children's conditions in the rehabilitation department ward. The original triple rooms were transformed into a double room to enable the treatment of severely sick children coming from other places. A M/G/2 queuing model with priority was also applied to analyze the state of patient admissions. Moreover, patients in Nanjing were also classified into mild and severe cases. The M/M/1 queuing model with priority was used for analysis of this situation, so that severely ill children could be treated in time while patients with mild symptoms could be treated at home. This approach not only eases the bed tension in the ward, but also provides suitable conditions for controlling cross-infection.

The secure key rate of quantum key distribution (QKD) is greatly reduced because of the untrusted devices. In this paper, to raise the secure key rate of QKD, a device-independent quantum key distribution (DIQKD) protocol is proposed based on hyper-entangled states and Bell inequalities. The security of the protocol is analyzed against the individual attack by an adversary only limited by the no-signaling condition. Based on the formalization of Clauser-Horne Shimony-Holt (CHSH) violation measurement on local correlation, the probability of a secure secret bit is obtained, which is produced by a pair of hyper-entangled particles. By analyzing the secure secret bit, it is proven that, when both the polarization mode and the path mode contains entangled -states, the DIQKD protocol gets a better secure key rate than common Bell states.

An electronic contract is a contract signed by electronic means, which is widely used in electronic commerce activities. In recent years, with the rapid development of quantum cryptography technology, the quantum electronic contract has been widely studied by researchers. Supported by the basic principles of quantum mechanics, a quantum electronic contract scheme based on the single photon is proposed in this paper. In this scheme, two copies of the same contract are signed by both parties involved, and then a copy of each contract is sent to a trusted third party. The trusted third party verifies the signatures of both parties and compares the signed copies to determine whether the contract is valid. Compared with the previous scheme, this scheme is based on the quantum electronic contract signed by the single photon. Because the single photon is easy to prepare and operate, this scheme is simple and easy to implement. At the same time, the scheme does not need to exchange signatures between the two parties, which reduces the complexity of communication. Nevertheless, it requires both parties and the third party to be honest and trustworthy.

With the increasing number of network systems and users, there are a myriad of data generated by users' daily activities, then comes the big data era. The focus of this paper tries to realise user trust negotiation with the help of blockchain technology. Therefore, in this paper, how to not only detect a malicious user but also negotiate the users' trust value among network systems are discussed. The dominating work is as follows: firstly, a variety of decentralised systems form a federated system. Secondly, every user behaviour profile is anchored on the user behaviour blockchain among the federated system, which concludes the trajectory of a user's overall behaviours, on the basis of user behaviour profile, the trust negotiation model based on practical byzantine fault tolerance (PBFT) is proposed. Finally, a scenario based on the model is proposed and its safety problems are analysed, which makes a new try in dynamic negotiation of user trust.

At present, the provenance of electronic records is stored centrally. The centralized way of information storage has huge risks. Whether the database itself is destroyed or the communication between the central database and the external interruption occurs, the provenance information of the stored electronic records will not play its role. At the same time, uncertainties such as fires and earthquakes will also pose a potential threat to centralized databases. Moreover, the existing security provenance model is not specifically designed for electronic records. In this paper, a security provenance model of electronic records is constructed based on PREMIS and METS. Firstly, this paper analyses the security requirements of the provenance information of electronic records. Then, based on the characteristics of blockchain decentralization, and combined with coding theory, a distributed secure provenance guarantees technology of electronic records is constructed, which ensures the authenticity, integrity, confidentiality and reliability of the provenance information.

With the diversification of electronic devices, cloud-based services have become the link between different devices. As a cryptosystem with secure conversion function, proxy re-encryption enables secure sharing of data in a cloud environment. Proxy re-encryption is a public key encryption system with ciphertext security conversion function. A semi-trusted agent plays the role of ciphertext conversion, which can convert the user ciphertext into the same plaintext encrypted by the principal’s public key. Proxy re-encryption has been a hotspot in the field of information security since it was proposed by Blaze et al. [Blaze, Bleumer and Strauss (1998)]. After 20 years of development, proxy re-encryption has evolved into many forms been widely used. This paper elaborates on the definition, characteristics and development status of proxy re-encryption, and classifies proxy re-encryption from the perspectives of user identity, conversion condition, conversion hop count and conversion direction. The aspects of the existing program were compared and briefly reviewed from the aspects of features, performance, and security. Finally, this paper looks forward to the possible development direction of proxy reencryption in the future.

With the rapid development of E-commerce and E-government, there are so many electronic records have been produced. The increasing number of electronic records brings about storage difficulties, the traditional electronic records center is difficult to cope with the current fast growth requirements of electronic records storage and management. Therefore, it is imperative to use cloud storage technology to build electronic record centers. However, electronic records also have weaknesses in the cloud storage environment, and one of them is that once electronic record owners or managers lose physical control of them, the electronic records are more likely to be tampered with and destroyed. So, the paper builds a reliable electronic records preservation system based on coding theory. It can effectively guarantee the reliability of record storage when the electronic record is damaged, and the original electronic record can be restored by redundant coding, thus ensuring the reliable storage of electronic records.

Quantum authorization management (QAM) is the quantum scheme for privilege management infrastructure (PMI) problem. Privilege management (authorization management) includes authentication and authorization. Authentication is to verify a user's identity. Authorization is the process of verifying that a authenticated user has the authority to perform a operation, which is more fine-grained. In most classical schemes, the authority management center (AMC) manages the resources permissions for all network nodes within the jurisdiction. However, the existence of AMC may be the weakest link of the whole scheme. In this paper, a protocol for QAM without AMC is proposed based on entanglement swapping. In this protocol, Bob (the owner of resources) authenticates the legality of Alice (the user) and then shares the right key for the resources with Alice. Compared with the other existed QAM protocols, this protocol not only implements authentication, but also authorizes the user permissions to access certain resources or carry out certain actions. The authority division is extended to fin-grained rights division. The security is analyzed from the four aspects: the outsider's attack, the user's attack, authentication and comparison with the other two QAM protocols.

With the rapid development of e-government, e-commerce and self-media, a large number of electronic network records have been generated on the Internet. How to archive these resources has become a focus of attention in academ... | Find, read and cite all the research you need on Tech Science Press

Conditional proxy re-encryption allows a semi-trusted third-party proxy to convert Alice's ciphertext that meets a certain condition into another set of ciphertext. Meanwhile, the proxy cannot obtain any valuable information in the process. Nevertheless, a single re-encryption condition is difficult to meet the needs of practical applications, and the existing conditional proxy re-encryption scheme cannot flexibly control the conversion conditions. To solve this problem, this paper proposes a multi-conditional proxy broadcast re-encryption (MC-PBRE) scheme for file sharing systems. In our scheme, a single user can delegate the decryption rights of the encrypted file to a group of users. At the same time, users can set any number of conditions to control the user group decryption permissions. This paper demonstrates the security of the scheme for chosen-ciphertext attacks in the standard model. Furthermore, the program can resist collusion attacks, which means that the agent cannot collude with the user group to get the private key of the principal.

Quantum private comparison is an important topic in quantum cryptography. Recently, the idea of semi-quantumness has been often used in designing private comparison protocol, which allows some of the participants to remain classical. In this paper, we propose a semi quantum private comparison scheme based on Greenberge-Horne-Zeilinger (GHZ) class states, which allows two classical participants to compare the equality of their private secret with the help of a quantum third party (server). In the proposed protocol, server is semi-honest who will follow the protocol honestly, but he may try to learn additional information from the protocol execution. The classical participants' activities are restricted to either measuring a quantum state or reflecting it in the classical basis {vertical bar 0 >,vertical bar 1 >} . In addition, security and efficiency of the proposed schemes have been discussed.

The risk assessment system has been applied to the information security, energy, medical and other industries. Through the risk assessment system, it is possible to quantify the possibility of the impact or loss caused by an event before or after an event, thereby avoiding the risk or reducing the loss. However, the existing risk assessment system architecture is mostly a centralized architecture, which could lead to problems such as data leakage, tampering, and central cheating. Combined with the technology of block chain, which has the characteristics of decentralization, security and credibility, collective maintenance, and untamperability. This paper proposes a new block chain-based risk assessment system architecture and a consensus mechanism algorithm based on DPOS improvement. This architecture uses an improved consensus mechanism to achieve a safe and efficient risk assessment solving the problem of data tampering in the risk assessment process, avoiding data leakage caused by improper data storage. A convenient, safe and fast risk assessment is achieved in conjunction with the improved consensus mechanism. In addition, by comparing existing risk assessment architecture, the advantages and impacts of the new block chain-based risk assessment system architecture are analyzed.

With the wide application of information technology in urban infrastructure, urban construction has entered the stage of smart city, forming a large number of network electronic records. These electronic records play a vital ... | Find, read and cite all the research you need on Tech Science Press

With the broad application of information technology in urban infrastructure, urban construction has entered the stage of a smart city, forming many electronic records in urban construction. These electronic records play a vi... | Find, read and cite all the research you need on Tech Science Press