Abstract- In 2018, on September 23, the North Korean programmers had created and embedded malware to take instalment data from Indian ATMs and banks. The malware, known as ATMDtrack, started showing up on systems and is believed to be owing to Lazarus Group, a hacking bunch that has focused on banks, ATMs, and digital currency trades. Ransomware assaults have been there since 2005, it is a kind of pernicious programming that accesses documents or frameworks and squares client access to those documents or frameworks. Then, all documents, or even whole gadgets, are held prisoner utilizing encryption until the casualty pays a payment in return for an unscrambling key. The key permits the client to get to the records or frameworks scrambled by the program. Ransomware costs organizations more than 75 billion dollar for each year and the normal expense of a ransomware assault on organizations was 133,000 dollar. Damages from ransomware are required to ascend to 11.5 billion dollar this year, and another association has succumbed to ransomware at regular intervals in 2019, and at regular intervals by 2021. These attacks lead to the stealing of the customer’s details and data, i.e. their data is insecure. For the security purpose of the banks and customers’ accounts, our system entitled “Blockchain in Banking System” focuses on the security of the data of the customer using block chain technology. Utilization of encryption algorithm SHA-256 in banking system to store its transaction details on blockchain database instead of dealing with common database. Basically it uses a peer-to-peer network of computers to validate transactions, to make it more secure and decentralized, to avoid different cyber-attacks that happen on bank. We have implemented blockchain in banking system to make it more secure, corruption free and fast by using blockchain’s encryption (hashing) and decentralized feature.

Keywords –Blockchain, Encryption, Ransomeware