Algorithm Weaves Secret Messages into Dance Music

By Nathaniel Scharping | August 24, 2016 3:54 pm
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(Credit: PHOTOCREO Michal Bednarek/Shutterstock)

In Ibiza, an island in the Mediterranean Sea, the hypnotic “thump thump thump” of the club music could actually convey much more than a call to dance.

Krzysztof Szczypiorski, a researcher from Poland, has developed a technique to hide messages inside dance music using subtle variations in tempo. By raising or lowering the speed of the music at levels not detectable by humans, he transmits a series of Morse code-like signals that can be picked up by a computer program. The sonic dots and dashes are then put together to spell out a message.

More Than Just Bass

Ibiza’s club music is perfect for his method because it relies on consistent bass-and-hi-hat beats of the kind meant to inspire all-night dance parties with their driving rhythms. For the type of spy who likes to hang around the Spanish party scene, however, it also represents the perfect opportunity to send super-secret messages.

Listen carefully to the beginning of this song. Could you hear the hidden code?

Szczypiorski’s technique fits in with the long tradition of steganography — the practice of hiding secret messages in plain sight. As the thinking goes, the best secret message is one that doesn’t look like a message in the first place. The first recorded example of steganography is from around 440 B.C. when a Greek ruler inscribed a message into the shaved head of his servant and sent him on his way once his hair had grown back, with instructions to shave again once he arrived.

Audio steganography dates to the Renaissance, when specific notes were used to spell out hidden messages, and the practice (or rumors thereof) has even made its way into more modern music, such as the infamous “Paul is dead” line from “Revolution 9”. Szczypiorski calls his program StegIbiza — steganography perfect for Ibiza. He published the results of his work on the pre-print server the arXiv.

Audience Oblivious

To test his technique, Szczypiorski recruited an audience of ten people who either had formal music training or were professional musicians, and ten people who had no special experience. He played them instrumental samples of “Rhythm is a Dancer” by German group Snap! which he had modified to contain tiny variations in tempo.

Slowing down the tempo for a beat corresponded to a dash, while speeding it up conveyed a dot, and the whole thing spelled out “Steganography is a dancer!” When he changed the tempo by 3 percent, the shift was obvious to everyone, but when it was modified by only one percent, no one could tell. Between one and two percent, only the professionals heard a difference.

Szczypiorski also took his modified dance music to a more realistic setting — on outdoor party filled with regular listeners. There, he had a DJ manually shift the tempo of the song to gradually spell out his message to the casual dancers. In this setting, he could change the tempo by up to two percent without anyone noticing, although by the time the changes reached 4 percent, around half the party knew something was up. He didn’t go any further than that, because, as he reports, no one was interested in his music anymore.

The next time you’re in the club, listen closely. The DJ might just be trying to tell you something.

CATEGORIZED UNDER: Technology, top posts
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  • OWilson

    Sounds like a great plot for the next Bond movie.

    “James, there is an evil entity controlling the world through his subliminal diabolical plot. We must stop him before we all die of exhaustion on the dance floor. The model industry alone has been decimated by this evil genius. We suspect he has a girlfriend who is not getting enough runway fees.

    Your mission is to check out the Miami South Beach scene and talk your way past the rope lines, and find the fiendish plotter. His stage name is “Dr. D.J.”

    (Hey, I’ve seen worse Bond plots!) :)

  • ZXCV

    The only Holy Book to contain prophecy is the Bible. It’s said that about 28%-30%. If the Bible is what it claims to be, how would we know? Some prophesy is already fulfilled and some is future.
    In addition there are interwoven, integrated macro codes, a bit like the code in the music but its revelation spells that this is from beyond the constraints of time and space.
    Less spectacular devices are also found, like this music code. Looking at the book of Matthew, chapter one, there is the linage of Jesus. It’s reading may be laborious the because text is dry. That is unless you try to arrange in words a composition of a genealogy which you may fabricate with the following constraints based around the number 7.
    The number of words in your composition must have a total number of words that can be divided by 7, evenly, no remainder.
    The number of letters divisible by 7. Easy, a sceptic can do this no problem, but…
    The number of vowels and consonants each divisible by 7
    The number of words that begin with a vowel must be divisible by 7.
    The number of words that begin with a consonant must be divisible by 7.
    The number of words that occur more than once must be divisible by 7.
    The number of words that appear in more than one form must be divisible by 7.
    The number of words that occur in only one form must be divisible by 7.
    The number of nouns shall be divisible by 7.
    Only seven words shall not be nouns.
    The number of names in the genealogy shall be divisible by 7.
    Only 7other kinds of nouns are permitted.
    The number of male names shall be divisible by seven.
    The number of generations also divisible by 7.
    The research was by Dr, Ivan Panin, taken from the Greek language, which I’ve taken from Dr.Chuck Missler, his book, Hidden Treasures in the Biblical Text.
    My intent was not to challenge Discovery Magazine but to add to the idea of encoding.
    The macro codes in the Bible tend to authenticate the origin of the text, within the text. The nature and method of this integration isn’t a singular little puzzle but engages the body of the text in large sections.
    Bible believers you see, are NOT required to have or expected to have or develop, blind faith.

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