Embed Size (px)
Citation preview
The SudokuCipher
Leandros Andreou, Antonios Furfaro, Nefeli ZikouCryptology Course
Center for Talented YouthAnatolia College & Johns Hopkins University
Thessaloniki, Greece 12 July 2016
…Secure and fun
ScenarioWhen death strikes a old man his fortune is exposed to his greedy close relatives who are willing to do anything in their power to get the money.Might even override the law…
What should the old man do to protect his fortune so that only his beloved nephews have access to it?
This is where a trusted lawyer aids him to hide the chest with the money and provides his nephews the instructions after the death of their uncle.
But… the chest is LOCKED!!! How are they going to find the key?
How it works
How it works
Original plaintext.
Substitute letters with their position in the alphabet.
I
ProcedureFor example:
If the first Sudoku number is 5 then the first Key number will be the 5th text number.
There is no number written twice in a Sudoku so there is no order problem
Numbers from Sudoku give the order of numbers from text so even if the text had more words only nine numbers would be used
9 23
12 19
16 5
9 13
7
+ 9 19 12 13 5 16 9 7 23
Key Ciphered Text Password
Numbers from Sudoku give the order of numbers from text
Final Form:
Security9! = 362,880 different keys No brute forceOne attemptRandom password makes the situation harder
Why it’s good for the situation
● Fast and easy for the nephews● Low chance of mistakes● Impossible to solve if you don’t know the key ● Only one attempt before locking
Nephew A solves the Sudoku – Takes first box up left Nephew B
deciphers the text substituting each first letter with the number representing its position in the alphabet
They cooperate and use table A to find the correct order of numbers of table B.
Procedure
This presentation is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
Cite as: L. Andreou, A. Furfaro, N. Zikou, The Sudoku Cipher: Secure and Fun, Assignment in the Cryptology Course,Center for Talented Youth, Anatolia College & Johns Hopkins University, Thessaloniki, Greece, 12 July 2016
Nefeli Zikou is a highschool student (K10 grade) in Alexandroupoli, Greece and a member of the Amateur Astronomy Club of Thrace, Greece. She has attended three Summer Schools in Mathematics (2014-2016, organized by the Hellenic Mathematical Society), a Summer School in Modern Physics (2016, organized by the Hellenic Society of Physics, and a 3 week Residential Summer Program Johns Hopkins Center for Talented Youth, organized in Anatolia College, Thessaloniki, Greece. She has successfully participated in a number of national mathematics and physics contests. Nefeli is a native Greek speaker and holds a Cambridge Certificate of Proficiency in English.
Email: [email protected]
Slideshare: http://www.slideshare.net/NefeliZikou
![Classical Cryptography. p2. Outline [1] Introduction: Some Simple Cryptosystems The Shift Cipher The Substitution Cipher The Affine Cipher The Vigen è](https://img.pdfslide.net/doc/110x75/56649d575503460f94a359a3/classical-cryptography-p2-outline-1-introduction-some-simple-cryptosystems.jpg)
