Abstract
This project examines how blockchain technology can enhance data security and reliability for web applications. In this article, ways to improve data security on online course platforms that utilize blockchain technology are explored. To clarify, online course platforms are web-based applications that enable users to access course materials online. These platforms often deal with sensitive data which, if compromised, can cause significant harm to users. Unfortunately, this information is often the target of fraudulent operations and illegal actions aimed at stealing personal data that can be used for authentication on various platforms. This article identifies the weaknesses of these sites and discusses the importance of using complex technologies to safeguard web resources effectively. This research explores how blockchain technology can protect from common web application attacks, which are often aimed at the user authorization process involving the transmission of identification and authentication data from the user to the website database. The study outlines the key components of blockchain technology, including hash function, hash value, data structure, and blockchain classification. Additionally, the study presents a transaction block model for a web course developed using blockchain technology.