Cracking the message in a bottle

Later this week on 28 January, the National Museum of Computing will host a virtual talk exploring the world of unsolvable encryption codes.

The “uncrackable” encrypted messages found in a number of bottles washed ashore in Hamburg between 2016 and 2019 may be drug related, or they may be part of a hoax. But encryption has long been used to share classified information. In the Cold War, it was used by spies and in 2012, a message among the bones of a pigeon found in a chimney in Surrey have been linked to the D-Day landings.

In their virtual talk, Elonka Dunin and Klaus Schmeh plan to explore codes such as the encrypted Voynich manuscript, the infamous cryptic messages from the Zodiac killer and the code inscribed on Kryptos, the mysterious sculpture located at the centre of CIA headquarters.

Computer Weekly spoke to Dunin and Schmeh ahead of their virtual talk to explore why the general public is intrigued by uncrackable encryption keys and codes.

“My initial interest began with Kryptos,” said Dunin. “It's one of the most famous codes in the world, and has not been cracked.”

Dunin is a co-founder and co-leader of a group of cryptographers who are working to crack the final cipher on the famous sculpture. She said that during her work on Kryptos, she was being contacted by many people asking whether there was a list of famous encryption codes that had not yet been cracked.

“There really wasn’t a prioritised list of famous unsolved codes, so I decided to make a web page,” she said. The page was just a simple page of text, but, according to Dunin, it had attracted millions of visits.

Asked why she though people were so interested in these codes, Dunin said: “Well, it’s a mystery and people love mysteries, whether they are murder mysteries or jigsaw puzzles that they are going to have to solve. It is also the sense of doing something that no one else has ever done before, like climbing to the top of Mount Everest. It’s the idea that there is something millions, or at least thousands, of people have worked on and no one has been able to solve.”

Rather like finding buried treasure, the people trying to crack these codes believe they are the only ones who will ultimately solve the puzzle, said Dunin.

Dunin’s own interest in codes began when she was a child. “I've always been interested in codes and ciphers since I was a little girl,” she said. “I would go to the dime store and there would be crossword puzzle magazines. Sometimes at the end, they would have little codes. I would buy the magazine, do the crypto codes and ignore the rest of the crossword puzzles.”

As an adult, she took part in encryption challenges and attended hacker conventions. At one of these events, she met Schmeh. The pair recently collaborated on a new book, Codebreaking: a practical guide.

Schmeh runs the Klausis Krypto Kolumne blog, looking at encryption history and unsolved encryption mysteries. According to Dunin, Schmeh is the most prolific crypto blogger in the world.

Describing the popularity of his posts, Schmeh said: “Usually the most popular articles are the ones that have a relationship to crime.” Especially popular are the posts that look at unsolved crimes, he added. “This is really fascinating – the idea of armchair detectives solving crimes.” 

For Schmeh, one of the most interesting crimes involved a wife murderer in the 1880s who created encrypted messages while waiting for his trial in jail. “They are still unsolved after 140 years,” he said.

Asked why he thought the murderer would would create an uncrackable message, Schmeh said: “There’s the option that it is all just a hoax, but there are a lot of open questions about this case.”

The murderer was eventually hanged for killing his wife, but Schmeh said he may also have murdered two previous wives. “It is possible he was writing about his previous wives, but it could just be a meaningless collection of symbols on sheets of paper. Nobody knows.”

Dunin described another case in which prison guards were able to intercept an encrypted message from a prisoner awaiting trial, sent to someone he was collaborating with on the outside. The message gave the collaborator instructions to find and destroy some evidence that could be used to convict the prisoner, but the code was cracked.