One of the world's fastest developing property markets is also in one of its least likely places — North Korea.

Even though the buying and selling of houses and apartments is illegal, it is becoming more widespread and sophisticated, said defectors as well as experts who study the ruined economy.

On paper, the socialist state owns all property. But the percentage of North Koreans who are buying their own home — as opposed to waiting for the government to assign one — is growing rapidly, surveys of defectors show.