Keybase is a centralized key directory that maps social identities to encryption keys for identity validation purposes. It also offers end-to-end encrypted chat and cloud storage. Historically, Keybase has supported Twitter, Github, Facebook, Reddit, Hacker News, and Bitcoin / zCash wallets In addition to all of these, it now also supports Mastodon integration.

Although this is the product of an open and ongoing dialogue between Eugen and the Mastodon user community, not everyone in the fediverse is completely on board with the idea, and there are some semantic elements that aren’t entirely clear. For instance, although Keybase currently supports 31 different instances, and it reserves the right to be selective about which instances will ultimately be able to use the service.

There are also some voices within the fediverse expressing the concern of using a closed source, centralized service for key storage and identity validation, and whether that has any implications for the federated social web.

At the very least, Keybase is now an option for those who want to use it. For those who don’t, they can instead opt into the “rel=me” validation method, in which an instance and a website can validate against one another