Cryptologic Bytes

"On This Date in History" Calendar

1969: 1st Message Sent on DoD ARPANET

Sunday, October 29, 2023

29 October 1969: First message was sent on Department of Defense-funded ARPANET, the forerunner of the modern Internet.

The first message sent over the ARPANET was from Leonard Kleinrock’s UCLA computer by student programmer Charley Kline at 10:30 pm on October 29, 1969, to the second node at Stanford Research Institute’s computer in Menlo Park, California.

The message was simply “Lo.”

"The message text was the word login; the l and the o letters were transmitted, but the system then crashed. Hence, the literal first message over the ARPANET was lo. About an hour later, having recovered from the crash, the SDS Sigma 7 computer effected a full login." (Wikipedia)


Check out the Cryptologic Bytes Archives for a wide variety of articles on all topics related to cryptology, codes and ciphers, related publications, Museums, and more.