Since the dawn of the internet, computer scientists have sought for a way to transact value digitally.  There are three basic questions involved when trying to do so:  How can I trust that digital money is genuine and not counterfeit?  How can I know that the currency can be only spent once (the double spending problem)? How can I be sure that only I maintain control over my digital tokens?  The invention of the Bitcoin protocol in 2009 and other digital currencies show how these problems can be overcome with cryptographic math proofs.  In this presentation I show many of the concepts involved in creating a protocol that obtains distributed consensus for an immutable global ledger, without the need for a central issuing or governing authority.  These include hash functions, merkle roots, digital signatures, and proof of work algorithms.  Application of the protocol creates economic incentives to secure the ledger against malicious tampering.  Finally, I discuss personal methods for securing digital tokens.