Web Server Integrity Protection Using Blockchain Most web applications use a remote web server to store a wide range of client data e.g., financial records, breaking news, stock prices, weather forecast, and medical record. In this model, a web application is completely dependent on integrity of remote server. A hostile or compromised web server may lead to security breach of client data or compromise query results. Due to explicit trust on the remote server, if an attacker gets control over the web server, one cannot guarantee the data security even if clientside is secure. One can imagine that if an attacker tampers critical data like stock prices or diagnostic medical records of patient; present on a web server that is to be used in decision making, it can cause some severe monetary and health damages. Even if we cannot prevent the data from getting tampered, but we can detect if someone has illegally tampered it. Instead of being tamper resistant we have provided an efficient and secure tamper evident solution to this problem using permissioned blockchains. Proposed solution provides a strong evidence to data user (decision maker) that if data provided by server is tampered or not, even if server is complete control of an attacker. Using blockchain technology as a trust base, our practical solution guarantees the correctness and freshness of data with minimum overhead.

A Basic Framework of BlockchainBased Decentralized Verifiable Outsourcing With the development and application of blockchain technology, more and more fields are beginning to use blockchains for industrial innovation, In recent years. At the same time, the data integrity verification techniques based on blockchain have also attracted wide attention of researchers. However, the stateoftheart schemes are only using the structure of the blockchain on centralized server which cannot leverage the characteristics of the blockchain and resist malicious modification attacks. In addition, the centralized blockchain structure introduces additional storage and computing costs. In this paper, we propose a decentralized verifiable outsourcing framework based on blockchain networks, in which no administrators are required to be in charge of auditing and recording data changes.