/* * * * * * * * * * * * * * Running Instructions. * * * * * * * * * * * * * * If running in code play ground enter * * * * * * * * * * * * On Seperate Lines * * * * * * * * * * * * 1 your text to encode 3 or 2 your text to decode 3 * * * * * * * * * * * * * * * * * Advanced Caesar Cipher. * * * * Created by [A^dr3w]. * * 28/06/2018 * * * * Modified 29/06/2018 * * Modified 30/06/2018 * * Modified 01/07/2018 * * Modified 13/07/2018 * * * * * * * * * * * * * * * * * 13/07/2018 # Updated running Instructions. 01/07/2018 # Modified print() method. # Updated documentation. 30/06/2018 # bug fixed if only one word entered greater than 10 characters in length. 29/06/2018 # Made code public. # Supports upper and lower case characters. # Supports special characters and punctuation. * * * * * * * * * * Documentation * * * * * * * * * * This cipher uses a left shift that changes every 10 characters depending on what text you enter making it harder to crack. Try entering abcdefghi abcdefghi abcdefghi A normal caesar cipher with a nine character left shift would output rstuvwxyz rstuvwxyz rstuvwxyz Over time this repetitiveness makes the cipher easy to crack, this advanced cipher changes the left shift every 10 characters so the output is rstuvwxyz ijkmnopq zabcdefgh This makes the cipher stronger. Note only text encoded in this program can be decoded. */ import java.util.Scanner; public class Program { static Scanner sc = new Scanner(System.in); public static void main(String[] args) { System.out.println("\nAdvanced Caesar Cipher."); System.out.println("======================="); Program caesar = new Program(); caesar.start(); } void start() { p("\nEnter '1' to Encode."); p("Enter '2' to Decode."); p("Enter '3' to Exit\n"); String select = sc.nextLine(); if (select.equals("1")) { encode(); } else if (select.equals("2")) { decode(); } else if (select.equals("3")) { exit(); } else { p("Invalid selection please try again !!!"); start(); } } void encode(){ p("Enter a String to encode: "); String in = sc.nextLine(); p("You entered: \n"+ in); String words[] = in.split("\\s+"); String out =""; int word = 0, cipher = words[word].length(); int sCount = 0; for(int i=0;i< in.length();i++) { if (sCount == 10) { if (word+126) { cipher -= (26-words[word].length()); } else { cipher += words[word].length(); } sCount = 0; } if (in.charAt(i)>=65 && in.charAt(i)<=90) { if ((in.charAt(i)-cipher)<65) { out += (char)(in.charAt(i)+(26-cipher)); } else { out += (char)(in.charAt(i)-cipher); } } else if (in.charAt(i)>=97 && in.charAt(i)<=122) { if ((in.charAt(i)-cipher)<97) { out += (char)(in.charAt(i)+(26-cipher)); } else { out += (char)(in.charAt(i)-cipher); } } else { out += in.charAt(i); } sCount ++; } p("\nYour encoded String is:"); p(out); start(); } void decode() { p("Enter a String to decode: "); String in = sc.nextLine(); p("You entered: \n"+ in); String words[] = in.split("\\s+"); String out =""; int word = 0, cipher = words[word].length(); int sCount = 0; for(int i=0;i< in.length();i++) { if (sCount == 10) { if (word+126) { cipher -= (26-words[word].length()); } else { cipher += words[word].length(); } sCount = 0; } if (in.charAt(i)>=65 && in.charAt(i)<=90) { if ((in.charAt(i)+cipher)>90) { out += (char)(in.charAt(i)-(26-cipher)); } else { out += (char)(in.charAt(i)+cipher); } } else if (in.charAt(i)>=97 && in.charAt(i)<=122) { if ((in.charAt(i)+cipher)>122) { out += (char)(in.charAt(i)-(26-cipher)); } else { out += (char)(in.charAt(i)+cipher); } } else { out += in.charAt(i); } sCount ++; } p("\nYour decoded String is:"); p(out); start(); } void exit() { p("Thank you for using the Advanced Caesar Cipher."); } void p(String print) { System.out.println(print); } }