Norissa Lamaute, Alexa Piccoli, Li-Chiou Chen, and Andreea Cotoranu Musical Cryptography Norissa Lamaute, Alexa Piccoli, Li-Chiou Chen, and Andreea Cotoranu

Research Goals To create a musical cipher that the sender could use to mask a message effectively, not necessarily by making the message harder to decrypt, but rather by making the message sound inconspicuous and difficult to detect as cipher. To the unsuspecting ear, our messages will sound like regular tunes, but to someone expecting a secret message, the music would be simple to decode.

Cryptography Then main goal of cryptography is to create a way to protect information from an adversary There are different mathematical transformations one can use to convert plain text into cipher text including permutations, combinations, transpositions, etc. The message must be easy to encrypt but difficult to decrypt, unless the recipient of the message has a secret passcode or key.

Cryptography vocabulary Encryption = the process of converting plain text into cipher text. Decryption = the process of converting cipher text into plain text.

Music Theory There are 12 tones in a chromatic scale meaning that there are 12 keys black and white in between C and the following B on a piano A major scale uses 7 of the keys W-W-H-W-W-W-H

Music Theory cont. Key signatures show which black keys on the piano to use Find the next major scale key signature by using circle of fifths Use the reverse for the major flat scales (fourths) Inner circle shows relative minor keys.

Music Theory cont. Quarter notes take up 1 full beat and in a common time signature, there can be up to 4 per measure. An eighth note takes up ½ of a beat and in common time, there can be 8 notes per measure. A sixteenth note takes up ¼ of a beat and in a common time, there can be up to 16 per measure. A triplet note takes up ⅓ of a beat and in common time, there can be up to 12 per measure.

Substitution Cipher A monoalphabetic cipher (or substitution cipher) is the simplest type of cipherkey This cipher encrypts each individual character in the plaintext alphabet with an individual character in the ciphertext alphabet.

Substitution Cipher cont. Ex. Cesar Cipher If any iteration were to have the key of 2 or B, the alphabet would shift from ABCDEFGHIJKLMNOPQRSTUVWXYZ to BCDEFGHIJKLMNOPQRSTUVWXYZA As a result, the plain text message “HELLO” become cipher text “IDMMP.”

Purposed Musical Cipher The goal of our encryption cipher is to generate a cipher key that will abide by the conventions of music theory. We intend to avoid dissonance and uneven beats in a measure by creating a key that stays in one key signature in the context of a single major scale to generate a tune pleasing to the ear, regardless of the plain text composition.

Proposed Musical Cipher cont. The letters are ordered by their frequency in the English language. In order to generate a consonant cipher, we arranged the notes by fifths. We then assigned each individual letter a rhythm or beat division so that two letters with the same note can sound different

Proposed Musical Cipher cont.

Proposed Musical Cipher cont. Using this cipher, the plain text “hello” in the key of C major is encrypted into cipher text “C50 C100 A50 A50 A100

Existing Methods There are other methods for Musical Cryptography that have been researched. Variations of substitution ciphers are used. Our research differs in that we aim to make the music sound consonant by abiding to classical music theory standards. This research relies on the Ionic scale which generates a more harmonic cipher text.

Results and Future Work We were successful in creating a cipher table that generated consonant sounds, but the cipher itself does not have strong security. The application of the proposed cipher can be combined with existing public key or private key encryption algorithms It should also be limited to encrypting information that is short in length to make statistical analysis of the cipher text harder

Acknowledgements The authors would like to acknowledge GE Capital for funding the “STEM Women Achieve Greatness” program at Pace University. The funding made it possible for us to conduct a collaborative research workshop with high school girls at Pace University during spring 2016. The high school student participants, Allegra Copeland, Jenna Dolgetta, Kayley Lewis, and Kyra Wilkowski, were asked to contribute their own ideas for musical cryptography models, which were all taken into consideration when conducting this study.

The end. Thank you!