Most banks have 3rd party APIs that allow service calls for read only access to a given account. Thus removing the need for a bolt on service to store credentia

Most banks have 3rd party APIs that allow service calls for read only access to a given account. Thus removing the need for a bolt on service to store credentials... Most times the best you get is an XML feed of transactions, balances... If you're integrating with a financial institution that cant give u this. I'd go with paginated hash of the passwords stored in the data file with keys hashed in filed on the file system. I'd store the hash for the pages in a physical dongle attached to a server, with hardware discovery. You could paginate the dongles daily too... There are some off the shelf dongles that do this quite nicely.