Dress code: How a Winnipeg codebreaker cracked one of the 'world's top unsolved messages'

"Bismark Omit leafage buck bank."

That seemingly random string of words appears in something called the Silk Dress cryptogram, 23 handwritten lines on two sheets of crinkled paper that were discovered in a hidden pocket of a Victorian-era dress bought in Maine in 2013.

The lines seemed like an encoded message from the late 1800s, with references to North American cities, including Calgary and Winnipeg.

"There were lots of theories [about its meaning], from the American Civil War to simply instructions for dress-making," said Wayne Chan, a University of Manitoba computer research analyst.

For about a decade, it stumped the global cryptanalytic community and was even listed as one of the "World's top 50 unsolved encrypted messages" on the cryptology blog Cipherbrain.

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https://www.cbc.ca/news/canada/manitoba/code-silk-dress-cryptogram-1.7056758