Blockchain implementation in banks Implementation of Blockchain in banks is said to be the new trend now. My question is: Would the private blockchain be kept private in a bank or will it be shared among a group of banks (or even possibly among all the banks)?

In the later case, is there no confidentiality issue, since a bank can know the transactions which are done by its competitors or its competitor's clients?
Think of a blockchain-based implementation of the financial backbone as the modern-day equivalent of Automated Clearing House (ACH), the national standard for processing checks.

Based on banking documents and blockchain organizations focusing on blockchain-based solutions for the commercial banking sector the solution will be a permission-ed, national-level blockchain with each participating bank being allowed access to the network. In this affect each bank would also be a miner with no reward, just confirming the transactions are valid.

The matter of confidentiality will be determined by the customers, and will pick their method of banking accordingly.