A Study on Blockchain and Cryptography

This project explores the development of a decentralized chat application leveraging blockchain technology. Unlike traditional chat apps that rely on central servers, our application utilizes a blockchain network to securely manage messages and user interactions. By distributing data across a network of nodes, the system enhances security, privacy, and resistance to censorship. Users maintain control over their personal data, as the blockchain ensures that all messages are encrypted and immutable. This approach not only reduces the risk of data breaches but also fosters a more transparent and equitable communication environment. Our solution aims to address the limitations of conventional chat systems and offer a robust alternative for secure digital communication. With the rapid development of Internet technology in recent years, Electronic Commerce has been an inevitable product of the economy, the science and the technology. This project is an online bookstore. This application is developed using Android, PHP and MySQL. The main objective of the project is to create an online book store that allows users to search and purchase a book online based on title, author and subject. The selected books are displayed in a list format and the user can purchase their books online through credit card payment. Using this app the user can purchase a book online instead of going out toa book store and wasting time. The customer can purchase books online. Through a web browser the customers can search for a book by its title or author, later can purchase using credit card transaction. They should give the details of their name, contact number and email. The user can also give feedback to a book by giving ratings on a score of five. The Administrator will have additional functionalities when compared to the common user. He can add, delete and update the book details, book categories, member information and also assign a new user role. Keywords: Android, PHP, Online Book Store, Internet, Decentralized, Html, CSS, JavaScript.