In this module, we look at the potential of blockchain in managing identity. By the end of this week, you'll be able to describe five problems with our current identifier based systems. One is the need for some overarching proof of personhood like a birth certificate. Another is all the data we generate by other parties home. Whenever we access the large centralized systems we use for email, banking, health insurance, and so on, we need to identify ourselves. These identifiers can be government issued ID cards, self-selected passwords, or biometrics data like a thumbprint. These identifier based systems are tricky, they're generally weak. They're out of our control and they're a hassle to manage and to update. As we start to look at solutions for these problems, we'll describe the basics of what is called a self-sovereign identity system and a distributed one at that. Sovereign, meaning, we own it. By distributing such a system on a blockchain, we can resolve many of these tough issues. Along the way, we'll look at approaches to developing use cases and standards for identity management. These use various types of smart contracts like proxy contracts and controller contracts. Finally, we'll examine how blockchain can handle identity in the healthcare space, a place holding some of our most important personal data. Some new initiatives could dramatically improve how research is conducted. These could generate value for the people whose data is used to make scientific breakthroughs possible. For more on identity, see the section on what we call the menome in the new preface to the paperback edition of blockchain revolution, as well as take a look at the principle of identity in chapter three.