I am trying to encrypt a string using substitution cipher, the program doesnt show any errors but the output is not what is expected. On encryption it shows random characters whereas i want it to be encrypted by another letter. This is what I have done:
/* Encryption using substitution */
import java.io.*;
public class SSExp1 {
public static void main(String args[]) {
char[] ip= new char[20];
char[] op= new char[20];
char key = '3';
String b;
I want to encrypt a file and decrypt it on another host. For decryption on another host I guess I need to transfer the cipher... how can this be done? How can you write a Cipher to disk?Or am I completely on a wron track?
The following code is doing it already on one host:
I'm trying to make a simple Caesar cipher that takes in a String as the first argument and a integer shift as the second argument. Namely, there appears to be a problem with the loop and how I have declared the array - I want the converted characters to be put into a new array called newCharacterArray, converted back to a String and displayed in the command prompt window.
public class Caesar { public static void main(String inString, int k) { System.out.println("String: " + inString); char inStringArray[] = inString.toCharArray();
2) Specify what arithmetic operators to swap (+, -, /, *)
2) If an arithmetic operator is read (like a + sign etc) then we swap it with its opposite (- for example)
3) Once the swap is complete, the rest of the file stays the same even if more operators are in the file...it is then output to a file (I am going with 1mutation.java)
4) This is where it gets tricky....it then picks up where it left off to finish reading the + operators (or whatever was specified) and repeats steps 2-3 (but the operator that is already swapped gets left as it was / skipped) and the output is saved as 2mutation.java.
The most I have been able to manage is having it changed 1 operator or all of them at once. I deleted a lot of my work to start fresh / master one operator for the time being. Here is what I have:
This is the data file I am using. (see attached) The file should be .java or .cpp but I stuck with .txt for now. How to tackle this? Am I on the right track?
I am using AES/CBC/PKCS5Padding algorithm to encrypt/decrypt, it works fine across machines, since i am not using a Facrtory to create the secret . I am using constant SecretKeySpec and iv for the ciphers. This of course heart the security , and doesn't prevent the "man of the middle" problem .
I saw that there are ways with key generation with MAC , and RSA symmetric encryption , but i am not sure how to implement it , and how to it depends on local certificates or files .
We have been tasked to create a Vigenere Cipher. At this stage however, I am attempting to get the program to encrypt a phrase using a single letter key (Caesar cipher), before progressing to the final stage, implementing a functioning Vigenere Cipher. The code below is able to encrypt a word, capatalise it, remove white space and shift it a certain amount of places, given the provided letter. My problem is that because the single letter is a String, not a char, the phrase is being shifted incorrectly. For example, when the program is given the Inputs: This is a test with the single letter key A, the program shifts all the characters by 1. The output however should read THISISATEST as A is supposed to be 0.
import java.util.Scanner; public class VigenereCipher { public static void main(String[] args) { char c;
My assignment is to write a program that will encrypt and decrypt a sentence entered by a user but the encryption is to be random using an array. Can I convert my sentence(string) from char to int then create a random array to encrypt?
import java.util.Scanner; import java.util.Random; /*SentenceEncryptionProgram */ public class SentenceEncryption { string sentence; //sentence entered by user
I've been given an assignment for my Programming Fundamentals class that requires the user to enter a word/sentence to encrypt or decipher, as well as requiring the user to enter a key in which to encrpyt/decrypt the input by.
So a = no shift, b = a shift by 1 and so on.
But I'm completely lost as to what to do, and after searching for Vigenere Cipher topics, they look completely different to mine and (hardly) include prompts?This is my code:
/** * @(#)VigenereCipher.java */ import java.util.Scanner; public class VigenereCipher { public VigenereCipher()
I'm building casar cipher with using ASCII. I'm done changing lower and upper case alphabet, but I don't know how to fix my code for changing number 9 to <.
here is my class code.
public class SimpleMessageCipher implements MessageCipher { public String encode(String plainText,int shiftKey){ String cipherText=""; for(int i=0;i<plainText.length();i++) { //stores ascii value of character in the string at index 'i' int c=plainText.charAt(i);
I have been assigned to make a program that encodes and decodes a given message with the given key (spaced numbers, for example: 3 1 7 4 2 5). I'll post the code for all the classes that I am using below.
QueueInterface:
import java.util.*; public interface QueueInterface<T> { T dequeue() throws QueueUnderflowException; boolean isEmpty();
Because those are the ones I had to write myself, the others were given to us to use. As far as these classes go, they work fine without causing any errors from the input I give. For example if I enter a message and a key, it correctly encodes and decodes the message with the given key. What I'd like for you fine programmers to do is give feedback on those 6 classes. Like, suggestions on how to make them better or more efficient, neater, changing any of the methods to make them more efficient or prevent any errors beforehand, etc.
I have an program with an encryption and a decryption method, it works fine when i specify a name for the encrypted file, but i want the name for the encrypted file to be in cipher text, how do i do this and specify the path? i have marked out the "encryptionPath" specifically for specifying the location of the encrypted file which will have a cipher text name.
I was tasked with creating a program that encrypts a line of text (for example, CANDY) by shifting the letters X amount of times. For example, if the user inputs the sentence CANDY and selects a shift of 5, the output would be: HFSID. I got this part working fine. The issue I am having is with the decryption part of the program.
This is simply the reverse of the above, as the user would enter the phrase HFSID, with a shift of 5, and the program would output: CANDY. It works fine, all except for one letter, being the "F" letter. With my code, when I enter the above word to be decrypted it outputs: C[NDY
Obviously, that [ bracket is not an 'A'. I realise the issue falls with the equation, Here is my code:
public class SimpleEncryption {
/** * @param args the command line arguments */ static int answer; public static void main(String[] args) { String cipher = JOptionPane.showInputDialog(null, "Please enter a sentence or word that you wish to encode or decode. This program uses" + " a basic cipher shift.");
I have following Cipher Code and test for it. But I am getting following exception.
Java Code:
java.lang.IllegalStateException: Cipher not initialized at javax.crypto.Cipher.checkCipherState(Cipher.java:1672) at javax.crypto.Cipher.doFinal(Cipher.java:2079) at com.anjib.util.CipherUtil.encrypt(CipherUtil.java:67) at com.anjib.util.CipherTest.testEncryptDecrypt(CipherTest.java:23) mh_sh_highlight_all('java'); Java Code: public class CipherUtil { private static Logger log = Logger.getLogger(CipherUtil.class);
How can I write a method that takes a string with duplicates letters and returns the same string which does not contain duplicates. For example, if you pass it radar, it will return rad. Also i would like to know how can I Write a method that takes as parameters the secret word and the good guesses and returns a string that is the secretword but has dashes in the places where the player has not yet guessed that letter. For example, if the secret word is radar and the player has already guessed the good guesses letters r and d, the method will return r-d-r.
I am currently trying to make a calculator in Java. I want to use the String split method to tokenize the string of characters inputted. I thought I was using the String split method wrongly, because I had surrounded the characters I wanted to delimit with square brackets. However, when I removed the square brackets, the code threw an exception when I pressed the equal button. The exception was a PatternSyntaxException exception. Am I using the String split method wrongly? And why is the exception thrown? Here is my code:
import javax.swing.*;//import the packages needed for gui import java.awt.*; import java.awt.event.*; import java.util.Arrays; import java.util.List; import static java.lang.Math.*; public class CalculatorCopy { public static void main(String[] args) {
i am trying to write a class method which will take in a string and returns a string which is the reversed version of that string. it compiles fine but when i try to run it it states Main method not found in class StringReverse,please define the main method as public static void main(String[]args). I am new to java and cannot figure out
import javax.swing.JOptionPane; public class StringReverse { public String reverseString(String str){ JOptionPane.showInputDialog(null,"Please enter word"); char c = str.charAt(str.length()-1); if(str.length() == 1) return Character.toString(c); return c + reverseString(str.substring(0,str.length()-1));}}
I'm having trouble with the last few lines of the code. It's supposed to take a replacement string entered by the user and print out the new string. For some reason it's now allowing me to enter a replacement string
import java.util.Scanner; public class Project02 { public static void main(String[] args) { Scanner keyboard = new Scanner(System.in); System.out.print("Enter a long string: "); String lString = keyboard.nextLine();
[Code] ....
Output:
Enter a long string: the quick brown fox jumped over the lazy dog Enter a substring: jumped Length of your string: 44 Length of your substring: 6 Starting position of your substring in string: 20 String before your substring: the quick brown fox String after your substring: over the lazy dog Enter a position between 0 and 43: 18 The character at position 18 is x
Enter a replacement string: Your new string is: the quick brown fox over the lazy dog <------ isn't taking user input
I have a method for a button so when a user inputs something it then will get the string value and check it against the string value within the properties file to see if it exists.
The properties file is called GitCommands.properties that contains -- > key = value <-- in it
I realised I have not used it correctly hence why I keep getting errors - I am lost on how to use it, I think perhaps that may be the issue here? I need to reference the file but I am doing it wrong? When I do use that piece of code I get null pointer exception too...
JButton btnSearch = new JButton("Search"); btnSearch.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { FindSelectedKey();
[code] .....
I understand I am missing my piece of code where it states "//determine whether the string is equal to the property file key string" I understand the logic fine but not actually coding it.
I am trying to split a string based on length(example length 5) of the string. But I am having a issues with this substring(start, end) method. I get all substring which are of length 5. But if the last substring is less than 5 then I am not getting that last substring. But I need the last substring even if it is less than 5.
Code a Java method that accepts a String array and a String. The method should return true if the string can be found as an element of the array and false otherwise. Test your method by calling it from the main method which supplies its two parameters (no user input required). Use an array initialiser list to initialise the array you pass. Test thoroughly.
public class test { public static void main(String[] args) { Printhelloworld(); String[] verbs = {"go", "do", "some", "homework"}; printArrays(verbs);
I'm having trouble to compare two string from my LinkedList. I took me 2 days now trying figure out how to compare the current string to previous string in the linkedlist. Here is my code.
public int compareTo(LinkedListNode n){ //Compare two string String myHead = data.toLowerCase(); String comparableHead = data.toLowerCase();
How do I compare a String to each element of a string array?
For example:
int headscount = 0; if (coins[i].equals("heads")){ headscount++; System.out.println("b" + headscount); }
This doesn't give me the right value because the IDE says that equals() is an incompatible type. I also tried changing the "heads" to an variable, but the results remains the same.
So I'm creating a class which when given three inputs uses them as sides of a triangle and tells ther user what type of triangle it is, or if the input is invalid, tells them why it is invalid. I'm readin the input as a string and then trying to split it into a string array, from there checking to see if it has 3 elements.. in which the data is good at that point, and then converting them to ints and checking to see if they're negative ansd finally checking to see if they can work as sides of a triangle ie a+b >c, a+c >b , b+c >a.
I'm trying to split it into an array of strings but am getting an error, and can't seem to figure out why as this should be working from what I've read of the string.split method online.
import java.util.*; public class TriangleTest{ private int sideA; private int sideB; private int sideC; public static void main(String[] args){ TriangleTest triangle = new TriangleTest("3 4 5");
