ntroduction

Bitcoin is a decentralized digital cryptocurrency created by pseudonymous developer

Satoshi Nakamoto. The first paper on Bitcoin [1], also referred to as the original Bit-

coin paper, was published by Nakamoto in 2008. It provides a brief description of the

concepts and architecture schematics of the Bitcoin protocol. It was used as theoretical

groundwork for the first implementation of a fully functional Bitcoin client. However,

up until now, no structured and accessible protocol specification has been written. Al-

though the Bitcoin community has successfully created a protocol specification [2], it

requires solid prior understanding of its concepts and implementation. In this paper a

formal and accessible specification of the core Bitcoin protocol, i.e. excluding the P2P

overlay network, will be presented.