LONDON, Jan 2 (Reuters) - Digital currency bitcoin kicked off the new year by jumping above $1,000 for the first time in three years late on Sunday, having outperformed all central-bank-issued currencies with a 125 percent climb in 2016.

Bitcoin - a web-based “cryptocurrency” that has no central authority, relying instead on thousands of computers across the world that validate transactions and add new bitcoins to the system - jumped 2.5 percent to $1,022 on the Europe-based Bitstamp exchange, its highest since December 2013. (Reporting by Jemima Kelly; Editing by Louise Ireland)