Used by Nazis for encryption, the machine was bought by a collector from the flea market for 100 euros, who later put it up for sale at the Bucharest auction house Artmark.
Someone in Romania thought he'd made a fair amount of money when he sold an old typewriter for 100 euros at a flea market. He was wrong.
The "typewriter" was, in fact, a German Wehrmacht Enigma I, a World War Two cipher machine, and the collector who bought it put it up for sale at the Bucharest auction house Artmark with a starting price of 9,000 euros ($10,300).
On Tuesday, Artmark sold it to an online bidder for 45,000 euros.
"The collector bought it from a flea market. He's a cryptography professor and he knew very well what he was buying," Cristian Gavrila, the collectable consignment manager at Artmark, said.
Romania was an ally of Nazi Germany until 1944 when it switched sides and backed the allies. Historians say it may host many other cryptographic machines not yet discovered.
Last month, Christie's New York Books set a world auction record of $547,500 with its sale of a "four-rotor Enigma cipher machine, 1944," to an online bidder.
The Enigma was used to encode and decode messages sent by the various branches of the Nazi military.
However, British mathematician Alan Turing and his team at Britain's wartime code-breaking centre, Bletchley Park, cracked the codes.
Some say, their work shortened the war by two years.