If we go for human-readable and decentralized with reasonable security, we can look towards 'petname' systems, like the 'Address Book' software popular on the I2P network. Petnames are the subjective binding of public keys to shortened names, where a user resolves domain names to keys according to a combination of their own personal list (which can be easily expanded with specially-formatted 'address helper links') and the lists of third parties which they have chosen to trust (or which they have been bootstrapped into, thus trusting the bootstrapper by proxy). No need for environmentally unfriendly proof of work schemes or what-have-you. This falls on the 'less secure' point of Zooko's Triangle in the sense that, although it is very practical, decentralized, and usually avoids conflict, it does have trust-based security flaws if those providing their lists ('resolvers' if you will) manage to swap out keys for a petname without anyone noticing.