Your identity will be a program on the Ethereum blockchain. That program has an address that will be the unique key for your identity. That program will indicat

Your identity will be a program on the Ethereum blockchain. That program has an address that will be the unique key for your identity. That program will indicate which keys can act on its behalf, and will provide a mechanism to revoke keys and recover the identity if your keys are lost. Users will have to install something because browsers have no key signing mechanism. If you manage keys in a web page, that web page can access your keys. You'll need an extension or an app to manage keys for you. This approach sounds like a stretch, right? No website is going to use an authentication mechanism that requires a separate install. If that were the initial use case for this, I would agree. The real use for these identities is within decentralized applications. These apps don't run on servers and don't force you to use middlemen when you interact with other people. Decentralized apps don't shut down. They don't care where you live. They connect you with other people on the planet that want to connect with you to trade, communicate, or interact in any way you want. The two of you choose your own rules, not those of the companies or governments that stand between you.