I need to encrypt/decrypt file contents using RSA . But the default nature of RSA I could not upload files larger than 177 bytes for key length 1024 bytes . How it can avoid , I look it for a 100 times yet...
I attach my encryption files here ...
See attached files for more details ...
I want to create a java program that can be encrypt-decrypt alphabet from characters . Which is the shifting of the alphabet is starting from the the first character to increase 4 and 5 increased in the second character, increasing 6 at the third character, and so on..
Then when one of the characters increasement is more than the ascii code of 'z', that character will decrease from the variable i from the loop. This is the output of the program that i want:
Encryption:
Plain text: "abcz"
Cipher text: "egiz"
Decryption:
Cipher text: "egiz"
Plain text: "abcz"
This is my code for now:
package -;
public class - {
public static void main(String[] args) {
String enkripsi = "abcz".toLowerCase();
String dekripsi = "egiz".toLowerCase();
[Code] ....
What's wrong with my code? It won't work. Specially in the decryption.
I have to write an encryption/decryption program for a sentence entered by the user that uses arrays. Here is my code so far. I'm kind of lost on what to do next in the code.
import java.util.Scanner;
/*Program that encrypts then decrypts a sentence
Encryption
*/
public class Encryption extends java.swing.JFrame{
[code]....
For this week's assignment, I am supposed to create a java program that encrypt's a user's sentence, outputs the encrypted message, then decrypts the message, outputting the user's original message.
This is what I have so far. It doesn't compile the last few lines since that is not correct Java syntax.
Java Code:
import java.util.Scanner;
import java.io.*;
public class Decrypter {
public static void main(String[] args) {
String sentence;
final char REAL_ALPHA[] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
[Code] .....
So you can see I have "realAlpha" which are regular letters of the alphabet, and "codeAlpha" which are the letters I want to encrypt with. I want 'a' equal to 'z,' 'b' equal to 'y', 'c' equal to 'x' and so forth in that sort of reverse order, you know? So the word "apple" would encrypt into "zkkov."
I am stuck as to how to replace the letters in this way. You can see I tried fumbling with sentence.replace to switch the letters out between the two arrays. Also, I only barely understand arrays.
I am creating 2 different java codes for encryption and decryption separately based on RSA algorithm. The codes also involve swings for GUI. The problem with these codes are that my string is getting encrypted but after decrypting it,i do not get the string rather i get string of random numbers and alphabets. I am posting both the codes.
Encryption code:
import java.math.BigInteger;
import java.util.Random;
import java.io.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class cipher implements ActionListener
[Code] ....
Now the decryption code
import java.math.BigInteger;
import java.util.Random;
import java.io.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class decipher implements ActionListener
[Code] ....
The screenshots for respective codes are as attachments ....
I am trying to put together an encryption/decryption application that will essentially accept a sentence that is submitted, and spit out the encrypted version and then switch it back to the correct sentence. I have been told to nest my information in the class (rather than the main), but am having difficulty actually understanding how to do this. The error that Eclipse is throwing me is also that it "could not find the main class." Here is my code:
import java.util.Arrays;
import java.util.Random;
public class encryptingWords {
public static void main(String[] args) {
final int ALPHASIZE = 26;
final char[] Lalpha =
[Code] .....
I've written most of the code (along with another classmate) to get this to work, but I can't seem to return the encrypted value. I'm also trying to figure out how to separate the digits (or if I'm supposed to) to make the numbers encrypted. The main kicker is that we have to be using methods to return the final values. Everything compiles, (It compiles, but no results really.)
A company wants to transmit data over the telephone, but they are concerned that their phones may be tapped. All of their data is transmitted as four-digit integers. They have asked you to write a program that will encrypt their data so that it may be transmitted more securely. Your program should read a four-digit integer number and encrypt it as follows: Replace each digit by the remainder after (the sum of that digit plus 7) is divided by 10. Then, swap the first digit with the third, and swap the second digit with the fourth. Then print the encrypted integer. Do the encryption in a method and send the encrypted number back to main.
Here are the method headers: public static int encrypt(int num) // Takes num as a parameter and returns the encrypted value public static int getnum() // gets one number from the user Example: If the user enters 1234 they should see: 0189
import java.util.Scanner; //Needed for Scanner class
public class LNFI_LNFI_program2
{
public static void main(String[] args)
{
getnum(); //Calls for getnum() method
[Code] ....
We have a website used for downloading large files as large as 6gb and sometimes larger. We have all files in FTP server. The websit is JSP/Servlet /Tomcat combination. Below is code sample. I need a solution to increase the download speed. I understand it is bound to network bandwidth but are the steps that we need to take while we have such large files.I read about multipart downloads,gunzip streaming.
//first connect to FTP server and login and keep connection
Calendar cal=Calendar.getInstance();
startTime=cal.getTime();
fis=ftp.downloadFile(ftpclient,separator+resourceID);
response.setContentType("application/*");
response.setHeader("Content-Disposition", "attachment; filename="" + downloadFileName + "";");
byte[] bytes = new byte[1024];
[code]....
I need to download large amount files, what should I care, Is the following code have problem on download large files
private static byte[] load(String filename) throws IOException {
FileInputStream fis = new FileInputStream(filename);
byte[] data = new byte[fis.available()];
fis.read(data);
fis.close();
return data;
}
I want to encrypt and decrypt a txt file by using PGP.I completed my PGP Encryption.I'm getting an error in PGP Decryption. The error msg as follows
Quote:
Exception in thread "main" java.lang.IllegalArgumentException: Invalid PGP message
at com.newpackage.bouncy.PGPUtils.getDataList(PGPUtil s.java:502)
at com.newpackage.bouncy.PGPUtils.decryptFile(PGPUtil s.java:198)
at com.newpackage.bouncy.PGPFileProcessor.decrypt(PGP FileProcessor.java:56)
at com.newpackage.bouncy.Tester.testDecrypt(Tester.ja va:46)
at com.newpackage.bouncy.Tester.main(Tester.java:61)
I am getting this error in the following line of my code.
PGPObjectFactory factory=new PGPObjectFactory(PGPUtil.getDecoderStream(is));
=>> Object obj=factory.nextObject();//here i am getting obj as null
if (obj == null) {
//System.out.println("Invalid PGP Message");
//System.exit(0);
[Code] .....
Button Code:
private void DecryptBActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
final String plainText;
if (!areKeysPresent()) {
// Method generates a pair of keys using the RSA algorithm and stores it
// in their respective files
generateKey();
[Code] ....
Everytime throwing exception "javax.crypto.IllegalBlockSizeException: Data must not be longer than 128 bytes" in decrypt method.
I am getting error message on Java code that was developed by someone else and is supposed to work.
public String decrypt(String password) {
try {
// create the key and parameter spec
KeySpec keySpec = new PBEKeySpec(password.toCharArray(), salt, interactions);
SecretKey key = SecretKeyFactory.getInstance(keyFormat).generateSecret(keySpec);
AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt, interactions);
// create the cipher
[code]...
the error message is as follows: Access restriction: The type 'BASE64Decoder" is not API (restriction on required library '/usr/lib64/jvm/java-1.8.0-openjdk-1.8.0/jre/lib/rd.jar')I am using eclipse.
I have a program that encrypts and decrypts using the AES algorithm, but I have to specify the name of the encrypted file, and also specify the format of the original file as part of the name of the encrypted file. I will like to know how how to implement the following features into my code : 1.)I want the name of the encrypted file to be in cipherText 2.) i want the computer to be able to decide the file type(extension eg.txt) without me having to specify it, for example in my code if I am encrypting a .jpg file, I have to specify the name of the encrypted file as encrypt.jpg
Here is my code which i have tried to implement:
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.CipherOutputStream;
[Code] ....
To see if I could get the file name to be in cipher text but I got these errors:
Exception in thread "main" java.lang.NullPointerException
at java.lang.String.<init>(Unknown Source)
at EncryptDecrypt.encrypt(EncryptDecrypt.java:48)
at EncryptDecrypt.main(EncryptDecrypt.java:37)
I'm currently working on a RSA Encryption using Fast Exponential technique. As the numbers I'm working with will be very huge, I am forced to use BigInteger.
As this is the first time I'm using Big Integer, I encountered quite a number of issues. I'll try my best to explain the errors I'm facing:
1. I had done this step: BigInteger d;
So I'm currently trying to get d = 0;
However, I keep getting an error required: BigInteger, found int.
When I changed it to d = new BigInteger(0) , I get this error:
java:19: error: constructor BigInteger in class BigInteger cannot be applied to given types;
d = new BigInteger(0);
^
required: no arguments
found: int
reason: actual and formal argument lists differ in length
Part of Code:
public class BigFastExponential
{
BigInteger e; // public exponenet: all has this
BigInteger d; // private key: only key owner has this
BigInteger n; // public modulus: all has this
/**
* Create a LongRSA object for a public key holder, with just e and n.
*/
public BigFastExponential(BigInteger public_e, BigInteger public_n)
[Code] ....
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);
[Code] ....
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
[Code] ....
We currently have an application which uses JDBC to connect to the backend database (DB version - 11.2.0.3 ). The application uses a properties file in which the password for the db schema is hardcoded in plain text format. Due to security restrictions we have been asked to make sure the password is encrypted in the file and no direct access is made to the schema using the plain text password. Best options we can use to make this password encrypted both at Oracle DB side and Java side.
View Replies View RelatedWhat step to know to develop software..
View Replies View RelatedIn a program I created, I'm using a text file that contains some texts needed for the program. The method relevant to this is something like the following.
private String wordgen(){
try {
BufferedReader reader = new BufferedReader(new FileReader("src/Resources/adjectives.txt"));
Random rand = new Random();
int low = rand.nextInt(400);
String fil="";
int i=0;
while(i!=low){
[Code]...
The program runs fine in netbeans project but once the jar is created it does not corporate with the text file. ("null" is returned) How can I attach text files to jar and exe?
I am trying to create a file browse option in my jsp and later after browsing, all i want to do is to read that file in my jsp without saving it into that database so that i can perform encryption for it and save that encrypted file later into my database. please provide reference link so that i can refer to some applications and and move ahead with my work.
View Replies View RelatedI found an exercise online to create a small program . I have this code that I have done so far:
import java.util.Scanner;
public class Test {
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
long a = sc.nextLong(); long b = sc.nextLong();
long count = 0; // counter
[code]....
The program should read the numbers a and b and list how many numbers between a and b are divisible by either 2, 3 or 5. If the user types the number 5 and then 8.... it would look at all the numbers in between - 5,6,7,8 and check if any of them are divasable by either 2,3 or 5. And since the numbers 5,6,8 are it would return the number 3 to the user..Now the problem is that this program only works for small numbers, but when I try to input numbers such as 123456789012345678 and 876543210987654321... it doesn't run at all.
So there needs to be a quicker way on how the program checks the numbers divisibility instead of checking each one. Here is where I am lost. How to fix the program that it will read bigger numbers such as a=123456789012345678 b=87654321098765432..There must be a quicker way ...something that can modify the code so it finishes in the matter of seconds not hours. Something that will fasten the process of checking if the numbers are dividable.
I want to migrate some large application code base's from jdk1.4 to jdk1.6.
1. Is there any tool/s available that can be used for this migration (Because manually it is very difficult for a application with almost 15,000 java files and 15 * 10^6 KLOC within a limited time frame).
2. Steps that should be followed in such cases.
3, If any tool is not available for such activity what are the salient points that are needed to be considered while migrating.
I have a simple display method in a java project as given below:
public void displayInfo() {
for(Student student : studentdB){
System.out.println(student.toString() + "
");
}
I would want to use one of Swing components to display the students instead of displaying them on the stdout. How I could go about calling this method in some Swing components that can display all the students in the studentdb?
What I'm tasked to do, is to make a simple Java class that forms a "V" based on whatever height the user would desire, made out of stars "*", and spaces " ".
For example, if a user desires a "V" with a height of 3, it would look print out something like;
* *
* *
*
Where a "V" with a height of 5 would look something like:
* *
* *
* *
* *
*
(That one didn't look too good, but you get the point, it's suppose to be 5 "high" and shaped like a "V"). The problem I have, is that I don't see what loops within loops within loops I would need to build something like this.
All the easy stuff like asking the user what height they want and such, I can handle, but I don't see how this thing is suppose to be coded, to print out a decent-looking and right-sized "V" in the console.
public static void main(String[] args) {
int height = 3;
for (int i = 0; i < height; i++) {
for (int j = 0; j < 2/(height+1)+1; j++) {
if(j == i) {
[Code] ....
Looked like something of a good start, and it drew me half (!) of the "V" in the size I wanted. Am I on to it here, or am I on the moon in terms of progress? I need the entire "V", not just a nice "".
I am calculating an exponent without using BigInteger. However, I find that using long is not enough to handle my code. Is there a way to handle large numbers without using BigInteger?
public static void main (String[] args){
int base = 3;
int exponent;
long total = 1L;
boolean n;
Scanner input = new Scanner(System.in);
[code].....
I have an application which has 10 million rows and 1000 columns in Oracle. Each value has a different set of calculations that are stored in User Defined PLSQL functions.
Data is displayed in form of data grid. When a user updates any value, the calculation is performed using plsql function and value is stored in database. Is there an easy way through which calculation is performed on the fly and i get maximum performance ?