Packet switching — the fundamental technical principle underlying the Internet — was developed completely independently by two researchers on opposite sides of the Atlantic. Paul Baran, at RAND Corporation, publishes in 1961 the first technical analysis of "distributed communication networks" for surviving nuclear attack. Donald Davies, at the UK's National Physical Laboratory, independently arrives at the same concept between 1965-66, coining the term "packet switching" that becomes universal. ARPANET's designers (1969) adopted Davies's terminology; Baran's work influenced the distributed, resilient network philosophy.