scholarly journals Smart Contract Data Feed Framework for Privacy-Preserving Oracle System on Blockchain

Computers ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Junhoo Park ◽  
Hyekjin Kim ◽  
Geunyoung Kim ◽  
Jaecheol Ryou
Keyword(s):  
Privacy Protection ◽  
Web Server ◽  
External Source ◽  
Privacy Preserving ◽  
Data Verification ◽  
Internet Infrastructure ◽  
External Data ◽  
Smart Contract ◽  
Contract Language ◽  
The Web

As blockchain-based applications and research such as cryptocurrency increase, an oracle problem to bring external data in the blockchain is emerging. Among the methods to solve the oracle problem, a method of configuring oracle based on TLS, an existing internet infrastructure, has been proposed. However, these methods currently have the disadvantage of not supporting privacy protection for external data, and there are limitations in configuring the process of a smart contract based on external data verification for automation. To solve this problem, we propose a framework consisting of middleware of external source server, data prover, and verification contract. The framework converts the data signed in the web server into a proof that the owner can prove with zk-SNARKs and provides a smart contract that can verify this. Through these procedures, data owners not only protect their privacy by proving themselves, but they can also automate on-chain processing through smart contract verification. For the proposed framework, we create a proof using libsnark for server data and show the performance and cost to verify with Solidity the smart contract language of the Ethereum platform.

Enhancement of “Technique for Order Preference by Similarity to Ideal Solution” Approach for Evaluating the Web Sources to Select as External Source for Web Warehousing

2017 ◽  
Vol 6 (1) ◽  
pp. 1-16
Author(s):  
Hari Om Sharan Sinha
Keyword(s):  
Euclidean Distance ◽  
External Source ◽  
Main Concern ◽  
Ideal Solution ◽  
Multiple Features ◽  
Solution Approach ◽  
External Data ◽  
Order Preference ◽  
Topsis Approach ◽  
The Web

The main concern of this paper is to evaluate the web sources, which are to be selected as external data sources for web warehousing. In order to identify the web sources, they are evaluated on the ground of their multiple features. For it, Multi Criteria Decision Making (MCDM) approach has been used. Here, among all the MCDM approach, the focus is on “Technique for Order Preference by Similarity to Ideal Solution” (TOPSIS) approach and proposing an enhancement in this method. The conventional TOPSIS approach uses Euclidean Distance to measure the similarity. Here, Jeffrey Divergence has been proposed to measure the similarity instead of Euclidean Distance which includes all the symmetric distances during computation. The Euclidean Distance only measures unidirectional distance whereas the Jeffrey Divergence includes multidirectional distances. Unidirectional distance includes only distance in one dimension but multidirectional distances includes differences, so more relevant in web sources evaluation. Experimental analysis for both the variations of TOPSIS approach have been conducted and the result shows the enhancement in the selection of web sources.

APLIKASI PENCARI INFORMASI PERMINTAAN LAYANAN WEB YANG ERROR MENGGUNAKAN ALGORITMA BOYER-MOORE

2016 ◽  
Vol 1 (1) ◽  
pp. 001
Author(s):  
Harry Setya Hadi
Keyword(s):  
Data Storage ◽  
Computer Network ◽  
Web Server ◽  
Access Methods ◽  
Ip Address ◽  
String Searching ◽  
Common Process ◽  
Web Server Logs ◽  
Different Parts ◽  
The Web

String searching is a common process in the processes that made the computer because the text is the main form of data storage. Boyer-Moore is the search string from right to left is considered the most efficient methods in practice, and matching string from the specified direction specifically an algorithm that has the best results theoretically. A system that is connected to a computer network that literally pick a web server that is accessed by multiple users in different parts of both good and bad aim. Any activity performed by the user, will be stored in Web server logs. With a log report contained in the web server can help a web server administrator to search the web request error. Web server log is a record of the activities of a web site that contains the data associated with the IP address, time of access, the page is opened, activities, and access methods. The amount of data contained in the resulting log is a log shed useful information.

scholarly journals Research on Blockchain-Based E-Bidding System

2021 ◽  
Vol 11 (9) ◽  
pp. 4011
Author(s):  
Dan Wang ◽  
Jindong Zhao ◽  
Chunxiao Mu
Keyword(s):  
Data Transmission ◽  
Privacy Protection ◽  
Graph Isomorphism ◽  
Third Party ◽  
Business Logic ◽  
Core Concept ◽  
The Core ◽  
Blockchain Technology ◽  
Smart Contract ◽  
Bidding Process

In the field of modern bidding, electronic bidding leads a new trend of development, convenience and efficiency and other significant advantages effectively promote the reform and innovation of China’s bidding field. Nowadays, most systems require a strong and trusted third party to guarantee the integrity and security of the system. However, with the development of blockchain technology and the rise of privacy protection, researchers has begun to emphasize the core concept of decentralization. This paper introduces a decentralized electronic bidding system based on blockchain and smart contract. The system uses blockchain to replace the traditional database and uses chaincode to process business logic. In data interaction, encryption techniques such as zero-knowledge proof based on graph isomorphism are used to improve privacy protection, which improves the anonymity of participants, the privacy of data transmission, and the traceability and verifiable of data. Compared with other electronic bidding systems, this system is more secure and efficient, and has the nature of anonymous operation, which fully protects the privacy information in the bidding process.

scholarly journals A Transparent and Privacy-preserving Healthcare Platform with Novel Smart Contract for Smart Cities

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Abdullah Al Omar ◽  
Abu Kaisar Jamil ◽  
Amith Khandakar ◽  
Abdur Razzak Uzzal ◽  
Rabeya Bosri ◽  
...  
Keyword(s):  
Smart Cities ◽  
Privacy Preserving ◽  
Smart Contract

A user collaboration privacy protection scheme with threshold scheme and smart contract

2021 ◽  
Vol 560 ◽  
pp. 183-201
Author(s):  
Lei Zhang ◽  
Desheng Liu ◽  
Meina Chen ◽  
Hongyan Li ◽  
Chao Wang ◽  
...  
Keyword(s):  
Privacy Protection ◽  
Threshold Scheme ◽  
Protection Scheme ◽  
Smart Contract ◽  
User Collaboration

SSMBS: a web server to locate sequentially separated motifs in biological sequences

2009 ◽  
Vol 43 (1) ◽  
pp. 203-205 ◽  
Author(s):  
Chetan Kumar ◽  
K. Sekar
Keyword(s):  
Amino Acids ◽  
Web Server ◽  
Nucleotide Sequences ◽  
Regular Expressions ◽  
Biological Sequences ◽  
Sequence Motifs ◽  
Specific Order ◽  
The Web

The identification of sequence (amino acids or nucleotides) motifs in a particular order in biological sequences has proved to be of interest. This paper describes a computing server,SSMBS, which can locate and display the occurrences of user-defined biologically important sequence motifs (a maximum of five) present in a specific order in protein and nucleotide sequences. While the server can efficiently locate motifs specified using regular expressions, it can also find occurrences of long and complex motifs. The computation is carried out by an algorithm developed using the concepts of quantifiers in regular expressions. The web server is available to users around the clock at http://dicsoft1.physics.iisc.ernet.in/ssmbs/.

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