On Thursday, Internet pioneer Vint Cerf announced that Dr. David L. Mills, the inventor of the Network Time Protocol (NTP), passed away peacefully on January 17, 2024, at the age of 85. After Cerf learned of David's death from Mills' daughter Leigh, he posted the news on the Internet Society mailing list.
Dr. Mills created the Network Time Protocol (NTP) in 1985 to address an important challenge in the networked world: achieving time synchronization between disparate computer systems and networks. In a digital environment, where computers and servers are located around the world, and each system has its own internal clock, there is a strong need for a standardized accurate timing system.
NTP provides a solution by allowing computer clocks on a network to be synchronized to a common time source. This synchronization is critical for everything from data integrity to cybersecurity. For example, NTP maintains the accuracy of timestamps for network financial transactions and ensures the accuracy and synchronization of timestamps for recording and monitoring network activity.
Mills first discovered the need for computer network time synchronization in the 1970s while serving at COMSAT and working on ARPANET, the precursor to the Internet. His solution adjusted the computer's time to within tens of milliseconds. NTP now runs on billions of devices around the world, coordinating time across continents and becoming the cornerstone of modern digital infrastructure.
As Nate Hopper detailed in an excellent 2022 profile in The New Yorker, Mills faces significant challenges in maintaining and growing the protocol, especially as the Internet continues to grow in size and complexity. His work highlights the often underappreciated role of critical open source software developers (a topic well explored in a 2020 xkcd comic). Mills was born with glaucoma, which reduced his vision and eventually led him to become completely blind. Mills handed control of the agreement to Harlan Stenn in the 2000s due to vision problems.
In addition to his work on NTP, Mills invented the first "Fuzzball Router" for NSFNET (one of the first modern routers based on the DECPDP-11 computer), created one of the first implementations of FTP, inspired the creation of "ping", and played a key role in the architecture of the Internet as the first chair of the Internet Architecture Working Group.
Mills' work has been widely recognized. He became a member of the Association for Computing Machinery in 1999 and a member of the Institute of Electrical and Electronics Engineers in 2002. In 2013, he received the IEEE Internet Award in recognition of his contribution to network protocols and timing during the development of the Internet.
Mills received his PhD in computer and communications science from the University of Michigan in 1971. At the time of his death, Mills was a professor emeritus at the University of Delaware, where he retired in 2008 after teaching for 22 years.