Cryptology

Tim Cahill

Ryan Church

Project Progress

• We have researched hill ciphers and are in the process of understanding them.

• We are also in the process of writing one.

• We also have been researching the Da Vinci Code to see how cryptology is involved.

Programming Example• Hill Cipher#include<stdio.h>#define ROW 3#define COL 3#define SIZE 3int main(){ int i=0, j=0, A[ROW][COL], first, second, third; char sec[SIZE];

printf("Enter your code: \n");

while(i<SIZE){ sec[i]=getchar(); printf("%c",sec[i]); i++; } printf("\n\n"); i=0;

while(i<SIZE){ printf("%d ",sec[i]); i++; } i=0;

printf("\n"); printf("Now enter 9 numbers you wish to use as a key: \n");

while(i<ROW){ while(j<COL){ scanf("%d", &A[i][j]); printf("%d ",A[i][j]); j++; } printf("\n"); j=0; i++; } printf("\n");

first = ((sec[0]-'a')*A[0][0]+(sec[1]-'a')*A[1][0]+(sec[2]-'a')*A[2][0])%26;

second =((sec[0]-'a')*A[0][1]+(sec[1]-'a')*A[1][1]+(sec[2]-'a')*A[2][1])%26;

third = ((sec[0]-'a')*A[0][2]+(sec[1]-'a')*A[1][2]+(sec[2]-'a')*A[2][2])%26;

printf("The encrypted first letter is %d \n",first); printf("The encrypted second letter is %d \n",second); printf("The encrypted third letter is %d \n",third); printf("\n");

return 0;}

Da Vinci Code

• Leonardo Da Vinci hid a lot of secrets in his paintings to protect certain things.

• For example: Evidently, Mona isn't quite the woman art historians thought she was. But only those who know the secret code can look at Leonardo da Vinci's famous portrait and see the happy hermaphrodite that lurks within.

• He also made device called a cryptext which is a device with dials on it which need to be rotated properly in order to open it, but if someone tried to force it open the message inside would be destroyed.

•

Da Vinci Code (cont.)

QuickTime™ and a decompressor

are needed to see this picture.

Summary of article

• Title- Spam and The Ongoing Battle For The Inbox.

• In this article a learning algorithm is used as a spam filter for security for all email users.

• This algorithm is so far advanced that it can detect key words such as money, free, and sex.

Summary (cont.)

• The way this relates to cryptology is that the algorithm can determine a certain email is garbage and encrypt it so it doesn’t reach the email user.

• Although there are ways to get around the algorithms detection, only advanced spammers know the small tricks such as HTML coding or ASCII codes.

References • Spam and the ongoing battle for the inbox.

Communications of the ACM, Volume 50, #2 (2007), pages 24-33.Joshua Goodman, Gordon V. Cormack, David Heckerman.

• Textbook: Invitation to computer science java versionEdition 3, Schneider, copyright 07. pages 600-607

• An overview of cryptography. Gary C. Kessler, may 1998 (23 January 2009). (website) www.garykessler.net/library/crypto.html#purpose

The Da Vinci Code:http://www.wired.com/culture/lifestyle/news/2003/04/58378