Identity based encryption. https://en.wikipedia.org/wiki/ID-based_encryption https://en.wikipedia.org/wiki/ID-based_encryption "Identity-based systems allow a

Identity based encryption. https://en.wikipedia.org/wiki/ID-based_encryption https://en.wikipedia.org/wiki/ID-based_encryption "Identity-based systems allow any party to generate a public key from a known identity value such as an ASCII string. A trusted third party, called the Private Key Generator (PKG), generates the corresponding private keys...." I think it's innovative and a bit of "thinking outside the box". You do need to ultimately trust a 3rd party (same as in PKI or WOT I guess?).