Bitcoin is a cryptocurrency as well as a new electronic payment system that has the potential to become a replacement/substitute for the traditional centralized payment systems that we utilize today. However, just like all other currencies, bitcoins must be stored somehow, which is usually done by a so-called wallet. There are many different types of wallets that all have advantages and disadvantages in terms of security, mobility and accessibility, in addition to many other factors that will not be discussed here.
In this thesis work, I will be presenting one specific type, which is an offline micro-controller based wallet, also known as a hardware Bitcoin wallet. Compared to any other types of wallets, the high security of the micro-controller based wallet makes it a point of interest. This will mainly be done by referring to a successfully working prototype, designed and programmed by me. I will also present some basic and more advanced theoretical concepts related to Bitcoin and the system of wallets, particularly the micro-controller based wallet as mentioned above.