Every field is improving day by day as technologies become advance. The banking industry needs to improve as well, due to face lots of pressure for their backward system and having a lot of issues, such as data storage, privacy, scalability, and transparency. These issues, forced to drive the banking system towards advancements. We know that the banking system is the core of finance. So, banking should adopt blockchain technologies due to their characteristics, such as decentralization, data privacy, immutability, transparency, etc. which could help the banking industry to cope with the issues of the traditional centralized banking system. There are many systems already proposed to the banking industry, that are based on blockchain techniques like transaction, auditing, trading, data sharing, off-chain, and on-chain systems. But there is no proper solution base system for banking that carries out the banking process flow using consortium and ensures to solve all issues discussed above. Keeping these problems, we proposed a theoretical model for the banking sector. This model uses the techniques of on-chain and off-chain transactions based on a consortium blockchain. In which, a user ID, with the public key, and a private key are provided to each banking user. In this model, data stored in a third-party database as an off-chain mechanism, and mapped using (public\private) Keys and user ID as an on-chain mechanism, which will be updated and validate periodically using Smart Contract. So, if data will tamper between two periodic checks, then this tempering gets caught. This technique ensures security. In this model consortium, P2P (Peer-to-peer) protocol is also applied to ensure data privacy and partial transparency. Also, three more services provide by this model are, registration, transaction to contractual party, and transaction to the customer from the bank. The first two services are handled off-chain and the third service is handled on-chain, which ensures authentication of registered clients. In this regard, as we mentioned above, that still no banking system proposed an idea to use the consortium technique yet. So, we compare our model with the previously proposed transaction models. Our proposed model covered almost all aspects required for a banking system. This model will help to implement a blockchain-based banking system, which is more robust, secure, transparent, and scalable.
