EFF's Sovereign Keys project aims to make the encrypted Internet more reliable and secure. It is a proposal to fix structural insecurities in the way that the Web, Email and other Internet protocols currently establish encrypted connections.
If deployed, Sovereign Keys will protect HTTPS and other uses of TLS/SSL against a wide variety of attacks, including attacks involving Certificate Authorities and domain validation, and attacks that involve downgrading or blocking encrypted connections. It operates by providing an optional and very secure way of associating domain names with public keys, augmenting other methods of publishing TLS/SSL keys, such as the existing system of Certificate Authorities or proposals to publish keys via DNSSEC.
You can read a high level overview or look at the detailed design document and list of issues that we're tracking in relation to the design. There is also a public mailing list for discussion of the design.