Cipher Cracking

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Supervisors

Honours students

Project guidelines

Project description

In this project you will attempt to solve a suspected murder that took place in Adelaide in 1948. This crime remains unsolved till today, but you can use engineering to bring our knowledge closer to the possible killer. You can read the details about the dead body and the circumstances [1]

Associated with the dead body was this secret code:

MRGOABABD
MTBIMPANETP
MLIABOAIAQC
ITTMTSAMSTGAB

(See the original photograph, as there may be an extra line, and some of the M's may be W's. Some people also think that the last "I" is really a "V". Also the last G is probably really a C). To this day code crackers have been unable to decrypt it.

Useful notes

As useful bits of information come to light, just list them here:

  • It was the Edward Fitzgerald loose translation's (plus his own additions and recombination of poems) of the Rubaiyat that was found on the body. Call number is 891.5 O5.B in the BSL.
  • The grave site is at West Tce Cemetery: grave site number 106 on row 12 of an area of the cemetery called "Plan 3." To find it, the easiest way is to go to a road called "Road 5 East" and then walk about 40 paces along row 12.
  • The ABC TV documentary show called Inside Story screened an episode of "The Somerton Beach Mystery" at 8pm, Thursday, August 24th, 1978 (Sydney time). Need to watch a DVD of it.

Approach and methodology

You have an advantage that as engineers you know more about information theory and statistics than the average policeman or code breaking expert. You will take a structured approach to writing software code to use a process of elimination to say whether particular coding schemes were used or not.

Start with the Playfair cipher and the Vigenère cipher to begin with and you should find that you can easily test the above sequence of letters to prove the Vigenère cipher was definitely not used. Then you can go onto exploring other encryption schemes

Note from Matthew: If you include the extra line, I'm not so sure you can prove it's not the Vigenère cipher. Also, given the date of the murder, and the dates of invention of some ciphers, there are some you could reasonably rule out (e.g. I doubt it's RSA for historical and technical reasons), however you can still implement them and try them out :). If you dig into some of the historical documents on the case you may find clues to possible decryption keys.

We would also like you to perform simple statistical tests to show if English was the most likely language or not in the original message. Also you should be able to prove if the code is the beginning letter of a sequence of words or is composed of whole words. A list of letter frequency rankings for different languages can be found here.

Then if you have time and if you are excited to take this project to a higher level you can start to check out the work of the great electrical engineer Claude Shannon and apply his techniques from information theory. You can measure the information content in the message in terms of bits for starters.

Possible extension

If you knock off this project too easily and are looking for a harder code cracking problem to try your software out on, you can progress to analyzing another famous unsolved mystery: the Voynich Manuscript

Expectations

  • We don't really expect you to find the killer, though that would be cool if you do and you'll become very famous overnight.
  • To get good marks we expect you to show a logical approach to decisively eliminating which coding schemes were definitely not used.
  • In your conclusion, you need to come up with a short list of likely possibilities and a list of things you can definitely eliminate that the code is not.
  • We expect you to critically look at the conclusions of the previous project groups and highlight to what extent your conclusions agree and where you disagree.
  • We expect all the written work to be place on this wiki. No paper reports are to be handed up. Just hand up a CD with your complete project directory at the end. One CD for each group member.
  • It is expected that you fill out [[ ]] each week, every Friday evening to briefly state what you did that week and what the goals for the following week.
  • It is important to regularly see your main supervisors. Don't let more than 2 week go by without then seeing your face briefly.
  • You should be making at least one formal progress meeting with supervisors per month. It does not strictly have to be exactly a month, but roughly each month you should be in a position to show some progress and have some problems and difficulties to discuss.
  • The onus is on you to drive the meetings, make the appointments and set them up.

Relationship to possible career path

Whilst the project is fascinating as you'll learn about a specific cold case—and we do want you to have a lot of fun with it—the project does have a hard-core serious engineering side. It will familiarize you with techniques in information theory, probability, statistics, encryption, decryption, and datamining. It will also improve your software skills. The project will also involve writing software code that trawls for patterns on the world wide web (exploiting it as a huge database). This will force you to learn about search engines and databases; and the new tools you develop may lead to new IP in the area of datamining and also make you rich/famous. The types of jobs out there where these skills are useful are in computer security, comms, or in digital forensics. The types of industries that will need you are: the software industry, e-finance industry, e-security, IT industry, Google, telecoms industry, ASIO, ASIS, defence industry (e.g. DSD), etc. So go ahead and have fun with this, but keep your eye on the bigger engineering picture and try to build up an appreciation of why these techniques are useful to our industry. Now go find that killer...this message will self-destruct in five seconds :-)

See also

References and useful resources

If you find any useful external links, list them here:

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