Java:
package com.crypt;
import java.util.Random;
public class Crypt3 {
private String unencrypted;
private int length;
private StringBuilder randomKey;
private Random rnd = new Random();
public String encrypt(String unencrypted){
this.unencrypted = unencrypted;
this.length = unencrypted.length();
getRandomKey(this.length);
char[] unencryptedAsCharArray = this.unencrypted.toCharArray();
for (int i=0; i<this.length; i++){
unencryptedAsCharArray[i]+=randomKey.charAt(i);
}
return String.valueOf(unencryptedAsCharArray);
}
public StringBuilder getRandomKey(int length){
randomKey = new StringBuilder(this.length);
for (int i=0; i<length; i++){
randomKey.append(rnd.nextInt(10));
}
return randomKey;
}
//decrypt
public String decrypt(String encrypted, String key){
char[] encryptedAsCharArray = new char[encrypted.length()];
encryptedAsCharArray = encrypted.toCharArray();
for (int i=0; i<encrypted.length(); i++){
encryptedAsCharArray[i]-=key.charAt(i);
}
return String.valueOf(encryptedAsCharArray);
}
public StringBuilder getKey(){
return randomKey;
}
}