Researchers develop low power Bitcoin algorithm and hardware

The island of Yap in Micronesia is known for its stone money called Rai. The natives carved disks of limestone up to 4 meters (13 feet) in diameter at nearby islands and precariously transported them home. The stones were much too heavy to move repeatedly, and once on the home island, the Yapese devised an oral ledger to keep track of ownership as money changed hands in exchange for goods and services. The stones had no utility, but they were a trivially verifiable proof of resources expended and served for hundreds of years as a hard currency.