WWI armistice was coded by local realtor

Marathon encoding session paved the way for peace

armistice that ended World War I
On Nov. 11, 1918, the day the armistice was signed that ended World War I, huge crowds of people flooded Nicollet Avenue. This photo was taken near 7th Street. Photo courtesy of the Hennepin County Library

Irving J. Luger, a realtor who lived in six different Southwest Minneapolis homes during the 1930s and ’40s, played a monumental part in ending World War I.

Born in 1895, Luger joined the Marines to serve the country during the Great War. When peace was reached 101 years ago, he was a 22-year-old sergeant — a “code clerk” working in encryption. He provided the indispensible link between Washington and the U.S. High Command in Paris and kept a world-changing secret for 11 critical days. 

A half-century later, in a 1971 interview with the Minneapolis Star, Luger shared what he remembered about his extraordinary service. After 50 years, he still knew every detail.

Irving J. Luger in 1939
Irving J. Luger in 1939

“It was Oct. 31, 1918, as I recall, about 11:30 p.m. A Marine guard on duty at 10 Rue St. Anne pounded on the door of my room and hollered, ‘Get up! There’s a general and a colonel waiting for you downstairs.’ The general was H.H. Harts. The colonel’s name was Quackenbush, an aide-de-camp to Gen. Pershing. 

“I dressed as hurriedly as I could and went downstairs. Gen. Harts said, ‘We have some important work for you, sergeant.’ He led the way to a car and we were whisked off to the U.S. Paris District Headquarters at 7 Rue de Tilsitt. 

“When we entered the headquarters building, all the lights were on and some of the big brass were standing around, including our adjutant general and chief of staff of the Paris headquarters. All seemed quite excited. I wondered what it was all about. 

“Col. Quackenbush asked me to show him the latest key to our code. I did. He asked me to code a short statement and I did. Then he asked questions about my coding experience. 

“After all that, he showed me several legal-sized typewritten sheets of paper, single-spaced. They were the terms of the Armistice, which the Allies had prepared for the Germans to sign. The terms were to be sent to Washington for approval. Col. Quackenbush said he wanted the document coded and transmitted to Secretary of War Baker that same night. 

“I told the colonel it would expedite matters if I had the help of my assistant, Cpl. Cassavant. A staff car was at once sent out to bring him in. 

“We started work about 1 p.m. and we worked straight through until 8 a.m. — a stretch of 19 solid hours. 

“When we finished we called the Signal Corps to come and pick up the message pronto and send it to Washington. The Signal Corps did. 

“Naturally, we were sworn to secrecy until terms of the Armistice were officially released Nov. 11.

“That coding job,” said Irving Luger, “was one of the highlights of my entire life.”

The curious reader is probably wondering about this encoding system that required two men to spend 19 hours to encode several typed pieces of paper. Conveniently enough, Southwest Minneapolis continues to be home to a cryptographer, Bruce Schneier, who also happens to be my husband. He explains the mechanism:

“During World War I, important messages were encoded using a variety of pencil-and-paper systems. Some systems replaced letters or words with groups of random letters, either according to an agreed-upon mathematical formula or based on pre-distributed dictionaries of code words known as ‘codebooks.’ A diplomatic message as important as this one was likely encrypted using one of these codebook systems.

“To encode this message, one of the Marines likely held the book. The other Marine would tell him words of the message, and he would look them up in the book and find the corresponding code word. ‘The’ might be ‘slcze.’ ‘Germans’ might be ‘qpszf.’ ‘Surrender’ might be ‘hlsaa.’ If a word didn’t appear in the codebook — and there were lots of those — each letter or, perhaps, group of two or three letters would be encoded. One of the two would write the code words down on another piece of paper. And they would go through the entire message this way, word by word and character by character.

“When they were done they would reverse the process and decrypt their message, in order to check their work and look for errors. The only way to proofread ‘slcze qpszf hlssa’ is to look those characters up in the book, group by group, and find their English-language equivalents.

“It’s a slow and laborious process, prone to errors, but at the time secure from anyone who didn’t have a copy of the codebook. Today, of course, we encrypt messages using computers and much more complicated mathematical systems. But two Marines working for 19 hours nonstop was state-of-the-art encryption technology in 1918.”

After the war, Sgt. Luger returned to Southwest Minneapolis, married and had kids. His son, Irving Jr., surely grew up knowing how proud his father was of his military service. Irving Jr. signed up when he turned 18, at the height of World War II. At 19 years old, Pfc. Luger was killed in action, leading his squad against an enemy outbreak in Alsace, France. He is buried overseas in a military cemetery. His father is buried in Fort Snelling National Cemetery.

If your house is included in the Hennepin History Museum photo collection, you can ask Karen Cooper for a house history by emailing her at [email protected]. Look for your Southwest Minneapolis house at tinyurl.com/hhm-houses.