جستجوی مقالات مرتبط با کلیدواژه « blockchain » در نشریات گروه « فناوری اطلاعات »

Intrusion detection systems seek to realize several objectives, such as increasing the true detection rate, reducing the detection time, reducing the computational load, and preserving the resulting logs in such a way that they cannot be manipulated or deleted by unauthorized people. Therefore, this study seeks to solve the challenges by benefiting from the advantages of blockchain technology, its durability, and relying on IDS architecture based on multi-node cooperation. The proposed model is an intrusion detection engine based on the decision tree algorithm implemented in the nodes of the architecture. The architecture consists of several connected nodes on the blockchain platform. The resulting model and logs are stored on the blockchain platform and cannot be manipulated. In addition to the benefits of using blockchain, reduced occupied memory, the speed, and time of transactions are also improved by blockchain. In this research, several evaluation models have been designed for single-node and multi-node architectures on the blockchain platform. Finally, proof of architecture, possible threats to architecture, and defensive ways are explained. The most important advantages of the proposed scheme are the elimination of the single point of failure, maintaining trust between nodes, and ensuring the integrity of the model, and discovered logs.

Due to the fact that in recent years, the discussion of removing the national entrance exam has been raised, this year, the 12th grade average has been set for high-demand fields, which has a direct impact of 40%, and for other fields of study, admission is based on the student's academic record. Therefore, safe storage of academic records and prevention of changing and manipulating students' grades is very important. Blockchain technology is of interest due to its unique features such as decentralization and completeness of data, on the other hand, smart contracts provide privacy and access control. A platform for implementing smart contracts is the Hyperledger Fabric blockchain network. In this article, a model for storing and retrieving students' academic records based on the Hyperledger Fabric blockchain is presented. In this model, the academic records of students, including the grades of specialized and general courses of the twelfth year, are stored in the form of a transaction. The evaluation organization, as the responsible organization, can retrieve these records and provide the candidate with the result of the evaluation (being accepted or not accepted in the field of the candidate's chosen location). This model considers comprehensiveness, decentralization, privacy and access control.

Financial transactions in Bitcoin are stored in a distributed database called the block chain. All transactions are publicly available for all network nodes with the aim of transparency and the possibility of verifying the correctness. But this blockchain transparency feature, exploited by transaction analysis techniques, can lead to the violation of users’ privacy and the disclosure of their identities. Researchers have proposed various techniques such as transaction mixing or fair exchange with the aim of improving privacy in Bitcoin transactions. In this paper, we present a new mixing scheme that overcomes some of the weaknesses of previous schemes. Obviously, in the proposed scheme, users can mix different amounts of Bitcoin in each round of the protocol implementation, which leads to achieving the result in a shorter time and at a lower cost. Also, this scheme is more resistant to denial of service attacks by malicious users.

Blockchain is a revolution in the field of information and communication technology, which was able to create outstanding developments in technology and the daily life of users and affect the internet payment process, by its benefits and applications. Investing in digital currencies has always been associated with a lot of risk due to the fact that their use is separate from the real world. Recently, this risk was largely covered by smart contracts. But the reality is that a smart contract without the use of strong information management systems like Oracle is often worthless. For the global adoption of blockchains, a reliable mechanism that facilitates communication between smart contracts and the outside world is critical. Without blockchain-based oracles, smart contracts are forced to rely solely on in-network information, which significantly limits their capabilities. Decentralized oracles have the potential to create security mechanisms that remove many systemic risks from the blockchain ecosystem. Blockchain oracles are one of the most important elements that make up the blocks, which operate with a safe, reliable function and without the need for mutual trust, to improve the blockchain ecosystem. In this article, we examined the application of Oracle architecture in the management of data structures in the field of blockchain.

The development and use of electronic health records (EHR) have had remarkable impacts on human life, such as improvements in the quality of medical care, better research results, and enhancements in treatment methods. Despite these improvements, availability, security and privacy concerns have remained to be very important in this field. In this article, we propose a decentralized and distributed system for electronic health records management with the help of the blockchain technology and its potential benefits. In this system, patient information is stored in the cloud. Also, the real owner of the electronic records is the patient, and with the help of smart contracts and encryption, he/she controls how to access his/her health information. In the proposed solution, the problem of sharing and storing the patients’ keys has been solved with the help of smart contracts. In addition, we proposed solutions to special cases which are raised by transferring the control of the records to the patients such as permissions for underage patients, in emergency situations, and after the death of the patient. Comparison of the related works shows that the proposed system has solved the problems of competing systems while maintaining a high level of privacy.

The Internet of Things (IoT) is intended to transform human life and unleash enormous economic benefits. However, inadequate data security and trust of the current IoT are seriously limiting its adoption. Blockchain, a distributed and tamper-resistant ledger, maintains consistent records of data at different locations, and has the potential to address the data security concern in IoT networks. While providing data security to the IoT, Blockchain also encounters a number of critical challenges inherent in the IoT, such as the huge number of IoT devices, the non-homogeneous network structure, the limited computing power, the low communication bandwidth, and error-prone radio links. This paper performs a comprehensive survey on the existing Blockchain technologies with an emphasis on the IoT applications, and identifies the Blockchain technologies which can potentially address the IoT’s critical challenges and hence suit the IoT applications. The above results along with the investigations on the potential adaptations and present enhancements in the Blockchain consensus protocols and data structures are fully elaborated.

Blockchain is a fundamental technology that has changed the recent digital world. In fact, blockchain technology is a digital ledger that records transactions in a secure and transparent manner and provides a decentralized method for verifying and maintaining records. In the field of digital economy, blockchain and digital currencies are intrinsically related to each other. Digital currency is a special form of digital money created on the basis of cryptography. Digital currency has a wide range of uses from online transactions, remittances, decentralized applications to commerce. Most digital currencies use blockchain technology to benefit from basic features such as decentralization, transparency, and immutability. In fact, blockchain is a technology that enables the effective use of digital currencies such as Bitcoin, Ethereum and other digital currencies. The purpose of this article is a science-based study based on blockchain developments and examining the use of blockchain in the digital currency industry, regulations, opportunities and upcoming challenges.

Today's technology, despite all its extensive benefits and services, has a rich potential to negatively impact the lives of children and adolescents. Cyberspace has led to the socialization of children and adolescents, but at the same time it has become a feature of curiosity and risk-taking, a space prone to commit crimes and specifically cybercrime. Of course, with the right education and safe monitoring tools, students can be informed and protected. By virtue of humanity and by virtue of social nature, man has unique characteristics and numerous strengths and weaknesses that have made him deserving of the support of others. This support is more important than any other stage from the beginning of life to the end of adolescence. In the meantime, the school is one of the most important supporters and guardians of children's and adolescents' education. In this article, by explaining the strengths and weaknesses of schools, sociability, sociability and anti-socialism of children, a review and new methods in using safe monitoring tools to control cybercrime in schools are presented. In addition to the use of monitoring tools, the proposed method emphasizes religious educational planning and uses the blockchain process to provide students with authentication in cyberspace. The high security of the blockchain process has been used to protect data against hacking attacks and to prevent identity fraud and data theft. The data is stored in a blockchain in a distributed manner and this process has been carried out with acceptable updates for 5380 schools located in Isfahan province and other users consisting of students and parents.

Today, cryptocurrencies in global payment systems have been proposed as a way to become independent of traditional banking and to get out of the control of banks and monetary policies of governments and reduce fraud in banking transactions and counterfeit them. In this paper, we create a comprehensive picture which includes the challenges of this field, and we analyze the results with a case study in both a quantitative and qualitative approach. According on the characteristics the challenges in this picture are divided to three levels: technological, environmental, and governmental characteristics. Also, according to the results obtained from the use of cryptocurrencies in different countries, we able to identify most of the national cryptocurrency challenges for Iran.

Blockchain technology is a decentralized data structure based on a chain to the ledger of interconnected data blocks. Blockchain stores new blocks in the ledger without having to rely on intermediaries in a competitive or voting mechanism. Due to the chain structure or graph between each block and its previous block, it is impossible to modify blockchain data. Blockchain architecture provides trust in a peer-to-peer network through nodes on the network according to different consensus algorithms. In this article, we intend to describe the mechanism of each consensus-based, voting-based, and distant-oriented graph consensus algorithm.