The global travel industry leaves almost every traveller with some amount of leftover foreign currency at the end of the trip. Most travellers are unable to use these leftover foreign currencies efficiently and profitably because exchange bureau rates do not favour the traveller nor accept low denomination coins. In this paper, we explore existing currency exchange systems for leftover foreign currency and consider prevalent challenges. We propose an innovative system, eMudra, for exchanging cash based leftover foreign currency by integrating smart kiosk-based systems with peer-to-peer currency exchange utilizing the concept of blockchain technology alleviating the challenges. A key component of our system advocates the role of wearable technology for secure identification with a kiosk-based transactions user interface. We have implemented, tested and evaluated eMudra components - the User Wallet and the Transaction Management Network as a permissioned consortium blockchain while simulating the kiosk interface and associated physical bill and coin exchange. Leftover foreign currency lying unused in the wallets and drawers of travellers is significant and can easily add up to billions if considered globally. Our blockchain based system, eMudra, can play an important role in bringing these currencies back into the global economy by making money deposit, management and exchange process easy and lucrative
