The following are a series of emails from Satoshi Nakamoto to Hal Finney, written in January 2009 as the two were working on early versions of the bitcoin software. Mr. Finney supplied these emails to The Wall Street Journal in the spring of 2014.

Since these emails were all coming from Nakamoto to Mr. Finney, they are Nakamoto’s responses to Mr. Finney’s emails, the body of which is marked by the > symbol. The exchange begins on Jan. 10, 2009, and ends on Jan. 24, 2009, and comprises the time they were working on versions 0.1.0 through 0.1.3 of the bitcoin software.