ECDSA public key recovery is discovered by whom? I'm looking for the history of the method (ECDSA public key recovery from signature). Where did this implementation first appear in (is it bitcoin?) and who discovered this method?
Update: in a footnote of his paper Generic Groups, Collision Resistance, and ECDSA (online since 2002-02-27), then published in Designs, Codes and Cryptography (2005), Daniel R. L. Brown wrote that

In ECDSA, the public key can be recovered from the message and the signature.

Then, acting as editor of the SEC 1 standard, he put there how such ECDSA public key recovery can be made. In this version v1.99 of 2009-05-21 with changes since v1.5 visible, that section appears as a late addition.
Thus it seems possible that Daniel R. L. Brown of Certicom came up with ECDSA public key recovery circa 2002. At least he knew about its feasibility. That vastly predates Bitcoin.