Bitcoin logo (bitcoin.jpg, yEnc)

One of the earliest images ever put on the chain, from May 2011 — an 8,776-byte JPEG of the Bitcoin logo, split across two transactions and wrapped in yEnc, the encoding Usenet used for posting binaries into text-only newsgroups. The first transaction opens with the yEnc header '=ybegin line=128 size=8776 name=bitcoin.jpg' and the second closes it with a CRC32 checksum, so the file announces its own name and size the way a Usenet post would.