String Encryption
I was asked to make a String encryption utility without using encryption API I basically had to come up with my own ecryption methodology! the program was to be able to encrypt a string and decrypt a string and to of course make it nearly impossible for anyone to figure out what the encrypted string says!
I would really love to get some advice and suggestions regarding my code! I know it is not fast and could indeed be faster but that wasnt the main focus in this case!
import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.Random;
/**
* This is a class which can be used to encrypt any sort of string,
* the class provides a simple encryption program which uses a scrambler/adder/replacer/swapper.
* The encrypted message is sent as a byte array which can then be formated and decrypted.
* If the message is infiltrated while traveling through a socket the thief
* wont be able to see the content of the message without the key or this class.
*
* @author Eudy Contreras
*
*/
/*
private static final char[] plain = {'A','B','C','D','E','F','G','H',
'I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X',
'Y','Z','Ö','Ä','Å','0','1','2',
'3','4','5','6','7','8','9'};
private static final char[] key = {'D','E','F','G','H','Ä','U','J',
'A','L','Z','Å','N','C','P','Q',
'W','S','T','Ö','I','V','R','X',
'Y','M','K','B','O','4','6','1',
'8','3','2','9','0','5','7'};
*/
public class Encrypter {
private static final char[] added ={'L','E','Z','G','H','Ä','U','J',
'A','D','F','Å','N','C','M','Y',
'W','S','B','Ö','I','V','R','1',
'Q','P','K','T','O','4','6','X',
'8','3','2','9','0','5','7'};
private static final int operationCount = 16;
/**
* This method will will used a simple key
* and encrypt a message
* @param message
* @return
*/
private static String obfuscate(String message) {
String caseCode = convertCase(message);
char[] caseBinary = new char[message.length()];
for(int i = 0; i<caseCode.length(); i++) {
if(caseCode.charAt(i) == 'A') {
caseBinary[i] = '1';
}
else if(caseCode.charAt(i) == 'a') {
caseBinary[i] = '0';
}
}
char[] upperCaseMessage = new char[message.length()];
for(int i = 0; i<message.length(); i++) {
upperCaseMessage[i] = Character.toUpperCase(message.charAt(i));
}
char[] code = upperCaseMessage;
for (int i = 0; i < code.length; i++) {
if(code[i] == 'A') {code[i] = 'D';}
else if(code[i] == 'B') {code[i] = 'E';}
else if(code[i] == 'C') {code[i] = 'F';}
else if(code[i] == 'D') {code[i] = 'G';}
else if(code[i] == 'E') {code[i] = 'H';}
else if(code[i] == 'F') {code[i] = 'Ä';}
else if(code[i] == 'G') {code[i] = 'U';}
else if(code[i] == 'H') {code[i] = 'J';}
else if(code[i] == 'I') {code[i] = 'A';}
else if(code[i] == 'J') {code[i] = 'L';}
else if(code[i] == 'K') {code[i] = 'Z';}
else if(code[i] == 'L') {code[i] = 'Å';}
else if(code[i] == 'M') {code[i] = 'N';}
else if(code[i] == 'N') {code[i] = 'C';}
else if(code[i] == 'O') {code[i] = 'P';}
else if(code[i] == 'P') {code[i] = 'Q';}
else if(code[i] == 'Q') {code[i] = 'W';}
else if(code[i] == 'R') {code[i] = 'S';}
else if(code[i] == 'S') {code[i] = 'T';}
else if(code[i] == 'T') {code[i] = 'Ö';}
else if(code[i] == 'U') {code[i] = 'I';}
else if(code[i] == 'V') {code[i] = 'V';}
else if(code[i] == 'W') {code[i] = 'R';}
else if(code[i] == 'X') {code[i] = 'S';}
else if(code[i] == 'Y') {code[i] = 'Y';}
else if(code[i] == 'Z') {code[i] = 'M';}
else if(code[i] == 'Ö') {code[i] = 'K';}
else if(code[i] == 'Ä') {code[i] = 'B';}
else if(code[i] == 'Å') {code[i] = 'O';}
else if(code[i] == '0') {code[i] = '4';}
else if(code[i] == '1') {code[i] = '6';}
else if(code[i] == '2') {code[i] = '1';}
else if(code[i] == '3') {code[i] = '8';}
else if(code[i] == '4') {code[i] = '3';}
else if(code[i] == '5') {code[i] = '2';}
else if(code[i] == '6') {code[i] = '9';}
else if(code[i] == '7') {code[i] = '0';}
else if(code[i] == '8') {code[i] = '5';}
else if(code[i] == '9') {code[i] = '7';}
else {code[i] = code[i];}
}
return String.valueOf(code)+"¤¤¤¤"+String.valueOf(caseBinary);
}
/**
* this method will decypher and encrypted string message
* @param message
* @return
*/
private static String DecypherEncryption(String message) {
String[] code_and_case = message.split("¤¤¤¤");
String codeMessage;
String caseMessage;
if(code_and_case.length == 2) {
codeMessage = code_and_case[0];
caseMessage = code_and_case[1];
}
else {
codeMessage = message;
caseMessage = null;
}
char[] code = codeMessage.toCharArray();
for (int i = 0; i < code.length; i++) {
if (code[i] == 'D') {code[i] = 'A';}
else if(code[i] == 'E') {code[i] = 'B';}
else if(code[i] == 'F') {code[i] = 'C';}
else if(code[i] == 'G') {code[i] = 'D';}
else if(code[i] == 'H') {code[i] = 'E';}
else if(code[i] == 'Ä') {code[i] = 'F';}
else if(code[i] == 'U') {code[i] = 'G';}
else if(code[i] == 'J') {code[i] = 'H';}
else if(code[i] == 'A') {code[i] = 'I';}
else if(code[i] == 'L') {code[i] = 'J';}
else if(code[i] == 'Z') {code[i] = 'K';}
else if(code[i] == 'Å') {code[i] = 'L';}
else if(code[i] == 'N') {code[i] = 'M';}
else if(code[i] == 'C') {code[i] = 'N';}
else if(code[i] == 'P') {code[i] = 'O';}
else if(code[i] == 'Q') {code[i] = 'P';}
else if(code[i] == 'W') {code[i] = 'Q';}
else if(code[i] == 'S') {code[i] = 'R';}
else if(code[i] == 'T') {code[i] = 'S';}
else if(code[i] == 'Ö') {code[i] = 'T';}
else if(code[i] == 'I') {code[i] = 'U';}
else if(code[i] == 'V') {code[i] = 'V';}
else if(code[i] == 'R') {code[i] = 'W';}
else if(code[i] == 'S') {code[i] = 'X';}
else if(code[i] == 'Y') {code[i] = 'Y';}
else if(code[i] == 'M') {code[i] = 'Z';}
else if(code[i] == 'K') {code[i] = 'Ö';}
else if(code[i] == 'B') {code[i] = 'Ä';}
else if(code[i] == 'O') {code[i] = 'Å';}
else if(code[i] == '4') {code[i] = '0';}
else if(code[i] == '6') {code[i] = '1';}
else if(code[i] == '1') {code[i] = '2';}
else if(code[i] == '8') {code[i] = '3';}
else if(code[i] == '3') {code[i] = '4';}
else if(code[i] == '2') {code[i] = '5';}
else if(code[i] == '9') {code[i] = '6';}
else if(code[i] == '0') {code[i] = '7';}
else if(code[i] == '5') {code[i] = '8';}
else if(code[i] == '7') {code[i] = '9';}
else {code[i] = code[i];}
}
if (code_and_case.length == 2) {
for (int i = 0; i < caseMessage.length()-1; i++) {
if (caseMessage.charAt(i) == '1') {
code[i] = Character.toUpperCase(code[i]);
} else if (caseMessage.charAt(i) == '0') {
code[i] = Character.toLowerCase(code[i]);
}
}
}
return String.valueOf(code);
}
/**
* Further increases the encryption level of the message by adding random numbers and characters
* to the already encrypted message the process can then be reversed with an additional key.
* @param code: the encrypted message
* @return
*/
private static LinkedList<String> scrambler(String code) {
Random rand1 = new Random();
Random rand2 = new Random();
Random rand3 = new Random();
Random rand4 = new Random();
String encryptedCode = Encrypter.obfuscate(code);
String[] case_and_code = encryptedCode.split("¤¤¤¤");
String cypher = case_and_code[0];
String codeCase = case_and_code[1];
LinkedList<String> cypherList = new LinkedList<>();
char[] cypherCharArr = cypher.toCharArray();
for (int index = 0; index < cypherCharArr.length; index++){
cypherList.add(added[rand3.nextInt(added.length)]+""+added[rand2.nextInt(added.length)]+String.valueOf(cypherCharArr[index]) + added[rand4.nextInt(added.length)]+(rand1.nextInt(99 - 10+1)+10));
}
cypherList.addFirst(""+(rand1.nextInt(999 - 100 +1 )+100));
cypherList.add(codeCase+rand1.nextInt(10));
return swapper(cypherList);
}
/**
* This method will unscramble and rebuild a scrambled string
* @param cypherList
* @return
*/
private static String unScrambler(LinkedList<String> cypherList) {
StringBuilder stringBuilder = new StringBuilder();
LinkedList<String> cypherListOutput = new LinkedList<>();
String caseCode = cypherList.get(cypherList.size()-1);
for (int index = 0; index < cypherList.size()-1; index++) {
cypherListOutput.add(String.valueOf(cypherList.get(index).toCharArray()[2]));
if(index>=1)
stringBuilder.append(cypherListOutput.get(index));
continue;
}
char[] rawCode = (stringBuilder.toString()+"¤¤¤¤"+caseCode).toCharArray();
char[] unscrambled = new char[rawCode.length-1];
for(int i = 0; i<unscrambled.length; i++) {
unscrambled[i] = rawCode[i];
}
return String.valueOf(unscrambled);
}
/**
* Swaps the content of the array the as many times as
* the operation count.
* @param code
* @return
*/
private static LinkedList<String> swapper(LinkedList<String> code) {
LinkedList<String> output = new LinkedList<>();
LinkedList<char[]> chars = new LinkedList<>();
String[] swapArray = new String[code.size()];
for (int index = 0; index < code.size(); index++) {
swapArray[index] = code.get(index);
chars.add(swapArray[index].toCharArray());
}
for (int iteration = 0; iteration < operationCount; iteration++) {
for (int i = 1; i < chars.size() - 2; i++) {
for (int r = 0; r < chars.get(i).length - 1; r++) {
char tempChar = chars.get(i)[r];
chars.get(i)[r] = chars.get(i + 1)[r];
chars.get(i + 1)[r] = tempChar;
}
}
}
for (int i = 0; i < chars.size(); i++) {
output.add(String.valueOf(chars.get(i)));
}
return output;
}
/**
* unswapps the content of the array in order to make it
* ready to be deciphered
* @param code
* @return
*/
private static LinkedList<String> unswapper(LinkedList<String> code) {
LinkedList<String> output = new LinkedList<>();
LinkedList<char[]> chars = new LinkedList<>();
String[] swapArray = new String[code.size()];
for (int index = 0; index < code.size(); index++) {
swapArray[index] = code.get(index);
chars.add(swapArray[index].toCharArray());
}
for (int iteration = 0; iteration < operationCount; iteration++) {
for (int i = chars.size() - 3; i >= 1; i--) {
for (int r = chars.get(i).length - 2; r >= 0; r--) {
char tempChar = chars.get(i)[r];
chars.get(i)[r] = chars.get(i + 1)[r];
chars.get(i + 1)[r] = tempChar;
}
}
}
for (int i = 0; i < chars.size(); i++) {
output.add(String.valueOf(chars.get(i)));
}
return output;
}
/**
* This method will convert a string into case holder
* which hold which character is upper case and which
* isn't.
* @param message
* @return
*/
private static String convertCase(String message) {
char[] caseHolder = new char[message.length()];
for(int i = 0; i < caseHolder.length; i++) {
if (Character.isUpperCase(message.charAt(i))) {
caseHolder[i] = 'A';
} else if (Character.isLowerCase(message.charAt(i))) {
caseHolder[i] = 'a';
}
}
return String.valueOf(caseHolder);
}
/**
* This method will take a case code holder
* and apply the case to the given message
* @param caseBank
* @param message
* @return
*/
private static String caseConverter(String caseBank,String message){
StringBuilder input = new StringBuilder(caseBank);
StringBuilder output = new StringBuilder(message);
for (int index = 0; index < input.length(); index++) {
char current = input.charAt(index);
char formatedString = output.charAt(index);
if (Character.isLowerCase(current)) {
output.setCharAt(index, Character.toLowerCase(formatedString));
} else {
output.setCharAt(index, Character.toUpperCase(formatedString));
}
}
return output.toString();
}
private static String printBytes(byte[] binaryEncription){
return new String(binaryEncription, Charset.forName("UTF-8"));
}
public static byte[] encrypt(String message){
String cypher = scrambler(message).toString();
byte[] encryption = cypher.getBytes(Charset.forName("UTF-8"));
System.out.println(printBytes(encryption));
System.out.println(Arrays.toString(encryption));
return encryption;
}
public static String decrypt(byte[] encryption){
LinkedList<String> list = fromStringToList(new String(encryption, Charset.forName("UTF-8")));
LinkedList<String> unSwapped = Encrypter.unswapper(list);
String unScrambled = Encrypter.unScrambler(unSwapped);
String decyphered = Encrypter.DecypherEncryption(unScrambled);
return decyphered;
}
private static LinkedList<String> fromStringToList(String list){
String[] newList = list.split(", ");
LinkedList<String> code = new LinkedList<String>();
for(int i = 0; i<newList.length; i++){
code.add(newList[i]);
}
return code;
}
public static void main(String[] args) {
System.out.println(Encrypter.caseConverter("AaaaAA", "eudycr"));
System.out.println(Encrypter.convertCase("Whats up man, how are you doing today?"));
System.out.println(Encrypter.obfuscate("Whats up man, how are you doing today?"));
System.out.println(Encrypter.scrambler("Whats up man, how are you doing today?"));
System.out.println(Encrypter.unswapper(Encrypter.scrambler("Whats up man, how are you doing today?")));
System.out.println(Encrypter.unScrambler(Encrypter.unswapper(Encrypter.scrambler("Whats up man, how are you doing today?"))));
System.out.println("");
System.out.println(Encrypter.DecypherEncryption(Encrypter.unScrambler(Encrypter.unswapper(Encrypter.scrambler("Whats up man, how are you doing today?")))));
System.out.println(Encrypter.DecypherEncryption("HIGYFS"));
System.out.println("");
System.out.println("");
System.out.println("");
System.out.println(Encrypter.decrypt(Encrypter.encrypt("Whats up man, how are you doing today?")));
}
}
Eudy Contreras
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lang-java