The Music Cipher

The Music Cipher

My smart phone wakes up every time the “Okay Google” advert appears on the TV, and it makes me wonder what other secret messages my devices could be receiving. Recently it was shown — with the Dolphin Attack — that Siri and Alexa could be provided with tasks which were hidden within songs.

This type of message passing is defined as a covert channel, and where we pass information through a channel which would not normally be used for information sharing.

So Mallory and Eve are being watched by law enforcement. Their messages are being read, and their emails are being opened. So Mallory decides to create a music cipher and to pass a secret message to Eve. He plays then a simple tune:

Eve listens and determines the score is in the key of C, with a C as Do, D as Re, E as Mi, F as Fa, G as So, A as La and B as Te:

She then maps to the notes to the timing and gets:

Next she counts in fours … and then represent the note for its location in the count (as the table below). So the mapping is L3 (L), T1 (O) and so on. Eve thus find the cipher word of “LONDON”.

So can you find the messages that Malory has hidden here:

and:

If you want to check your answers, try here: