In the earliest days of Ethereum, a novel concept emerged â instead of only signing codified transactional data with our Ethereum accounts, what if we made it easy to sign ANY piece of data? Though signing messages with private keys to make statements / attestations / pieces of data âcryptographically verifiableâ was not a novel concept, the proliferation of consumer-centric PKI in the form of âblockchain accountsâ made this a potential consumer-facing experience for the first time.