Blockchain-Integrated Dual Keypad Authentication System

With the increasing reliance on cloud storage, securing data against unauthorized access has become crucial. Various algorithms are implemented to maintain data confidentiality, integrity, and availability. However, centralized cloud storage lacks these essential security features. To enhance data storage methods, decentralized cloud storage is employed, with blockchain technology playing a key role in preventing data modification or deletion. Blockchain mitigates the risk of data tampering by storing information in interconnected blocks secured with hash values. The SHA-256 algorithm, widely used in secure banking frameworks, ensures robust hashing functions during data input, making it a preferred choice for implementing blockchain security. Hashing algorithms serve multiple security functions, including message authentication, consensus mechanisms, and mining operations, as well as custom blockchain development. Combining these techniques enhances data security and reliability for users accessing cloud-stored information. Additionally, encryption further strengthens data protection, and the Advanced Encryption Standard (AES) algorithm is specifically utilized in this study for both encrypting and decrypting data due to its strong security attributes. Keywords: Custom Blockchain, SHA-256 Algorithm, Hashing Functions, Consensus Algorithm, Distributed System, User Data Privacy, etc.