As Bitcoin continues to ride the wave of success in 2017, there have been many people and organisations warning of potential issues to come. The latest in this line is huge banking group BNP Paribas with their recent comments around the cryptocurrency.In their recent reported comments, BNP Paribas has essentially highlighted the lack of a central bank as the major factor that could hamper Bitcoin's future progress. They believe the long-term future of the cryptocurrency to be limited, as there is no lender of last resort as you would usually have with a centralised currency. BNP Paribas has stated that this lack of a last resort lender could cause major risks in the future for Bitcoin and also undermine monetary policy. On the back of this, it seems that the last big financial crisis is weighing heavily on their minds too. They are reportedly worried that another major crash could prove even worse for Bitcoin-based products with no central authority to step in.Of course, the answer to these points raised by BNP Paribas would be to implement a central institution to help regulate Bitcoin. However, this would go against the whole ethos of the cryptocurrency world, where open access to a decentralised digital currency with no financial intermediary in-between is paramount. As such, this is very unlikely to happen. It must be noted that many in the financial sector will take these latest comments around Bitcoin with a pinch of salt. It could be argued that this is just the latest traditional banking institution with a case of sour grapes over the way cryptocurrency has changed the landscape. Indeed, even BNP Paribas itself has started to implement Blockchain technology in some transactions, so it must place some future value on the digital currency explosion.