340 Cipher

Automates the process of encrypting and decrypting the 340 Cipher, a cipher that surrounds one of the most notorious Who Done It cases in American history.

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340-Cipher

Inspiration

On December 11th, 2020, only a few hours after Who Done It Hacks began, the F.B.I. announced that a coded message left by the infamous Zodiac Killer had finally been cracked, after 51 years of being a mystery. You can read the news article from the NY Times here. Given that the Zodiac Killer is one of America's most famous Who Done It cases, I was inspired to base my project around this groundbreaking news.

What it does

340 Cipher automates the process of decrypting and encrypting the complicated 340 Cipher. Given that it has only been one day since the official announcement that the cipher was cracked, 340 Cipher appears to be the only website currently offering automated encryption and decryption of the cipher. You can try it out yourself at 340cipher.co!

How we built it

Based on this YouTube video, published yesterday by David Oranchak, one of the codebreakers who cracked the cipher, I studied the decryption method of the 340 Cipher. Using jQuery connected to an HTML/CSS/Bootstrap frontend, I translated this algorithm into JavaScript. Developing this algorithm was the most difficult part of the project, as the cipher is incredibly complex (after all, it took 51 years to crack!) and has very limited documentation currently.

Once I implemented the logic behind encrypting and decrypting the cipher, I built out an interface for inputting each of the 73 symbols used by the Zodiac Killer in his ciphers.To make the site user-friendly, I added a method of easily importing and exporting encrypted messages, since they cannot be easily copied in plain-text due to the unique symbols.

To make the website look aesthetically pleasing, I used Bootstrap 4 to design the visual aspects of the site.

Challenges we ran into

Because this cipher was cracked so recently, there was very limited documentation to follow when developing the algorithm. I had to use a lot of trial-and-error to find an algorithm that consistently worked across every potential message.

Additionally, the Zodiac Killer did not include every character in the English language in his letter, so I had to make decisions about how to handle unknown letters for users of the website wanting to encrypt their own messages.

Accomplishments that we're proud of

I'm really proud that my site seems to be the first site offering an automated method of decrypting and encrypting the 340 Cipher.

What we learned

This was the most algorithmically complex hackathon project I have every created due to the complex nature of the cipher. I spent a lot of time learning how the cipher worked before I could even begin coding. Additionally, I learned a ton about cryptography, a field I do not any experience in.

What's next for 340 Cipher

I hope to further improve refine my algorithm as more information becomes available about the 340 Cipher. For example, there is still some debate over the specific ordering of words within the decrypted message, as well as debate over certain misspellings in the message.

I hope that my website will make working with this complicated cipher more accessible to a wider audience. I also hope it will encourage other codebreakers to join the community of Internet detectives trying to find a solution to the Zodiac Killer's final encrypted message, Z-13, which many believe contains the identity of the killer.

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