C++ :: How To Create Simple Encryption And Decryption Program
Apr 18, 2014
Write a program to do simple encryption and decryption. Encryption basically means to convert the message into unreadable form. In this assignment, it should be done by replacing each letter of a message with a different letter of the alphabet which is three positions further in the alphabet. Then, all the letters will be reversed. Decryption is the process of converting encrypted message back into its original message. Your program should use the following shifting method.
Note: You must use array.
#include <iostream>
#include <string>
using namespace std;
I am having trouble with an assignment. The assignment consists of a basic encryption and decryption program already written for me, I just have to write the encryption function. What we have to get the program to do is enter an integer and a text, and get the program to increment each letter in the text by the integer given. I did this by using a for loop and incrementing each value in the string by the integer.
However, I still can't get it to decrypt and I need the program to work with only a-z letters (if I increment each letter by 3 and I have the letter Z, it should go to Z+3 = C).
I attached the description of the attachment and below are the codes: The first file does not need to be edited.
Code: /*******************Programming Assignment 1***************/ /****************Caesar's substitution cipher**************/ /*****************YOU MUST NOT EDIT THIS FILE**************/ /****Substitute alphabets in a string using rotation key***/ /****Leave all other characters unchanged******************/ /****Confirm correct encryption by decrypting**************/
I just want to test AES from openSSL with this 3 modes: with 128,192 and 256 key length but my decrypted text is different from my input and I dont know why. Also, when I pass a huge inputs length (lets say 1024 bytes) my program shows `core dumped`... My input is always the same but it doesnt matter, at least for now. Heres the code:
We need an AES Encryption/Decryption program in C for college lab (Educational) purpose . So we cannot use any "aes.h" file for this . We need a C program which simulate the purpose of AES
Input : Text (e.g: Anes P.A) key (e.g:123op)
Output : Cipher Text using AES
I look this functionality done in a website : [URL] ....
I am trying to make a simple program for encrypting a char* with the XOR operator. The code compiles and links perfectly, but I get an Access violation runtime error:
#include <iostream> #include <cstdlib> #include <cstdio> #include <string> #include <fstream> using namespace std; int main(int argc, char** argv) {
what i think i need to create 2 int for the FOR loop to do the encryption but how am i to do it meaning the actual encryption itself what is that i check with?Also i think i need more than just the #include <stdio.h> library due to the file functions that i will need or is C having them built in? Also what is that about the program doing all this from DOS?
Create 2 programs with the names encrypt and decrypt that will encrypt and decrypt files respectively.The encryption and decryption will be done through a command line of DOS and the program should be as follows: encrypt file1 file2 key and decrypt file1 file2 key
Where: file1 is the source file file2 is the destination file key is the word with which we encrypt/decrypt file1
So when the user executes the command encrypt f1 f2 sunnyday the program will create a file with the name f2 which will have the contents of f1 encrypted with the key sunnyday.When the user executes the command decrypt f1 f2 sunnyday the program will create a file with the name f2 which will have the contents of f1 decrypted with the key sunnyday.
If the user gives a wrong key the program will continue to decrypt file1 but since the key is wrong the results will be unexpected.Finally the program must print the corresponding error messages in case of errors for example (There is no file 1).The program is expected to work corectly with not only plain text files but executable (exe) files etc.Also The program must be fully commented.
Note: The way the encryption will work is yours to choose but it is recommended that you encrypt every letter of the file with every letter of the key with the (start to finish and begin) technique meaning that if the key has 8 letters then the first leeter of the file will be encrypted with the first letter of the key, the second letter of the file with the second of the key, ..., the ninth letter of the source file with the first letter of the key, the tenth letter of the source file with the second letter of the key etc.
Back again with a random bug that I can't seem to track down. My error is in my main.cpp file. I get a C2248 error on line 54, there I'm doing:
t.makeEmpty(t.root)
I know why, because it's a private member...but it should have access in so far as everything is concerned. I double checked my makeEmpty code and it's good to go so far as I can tell. I can't quite iron out where the disconnect is.
Is it possible to encrypt a folder and put it in a file container. Would I need to store the header key and other stuff my self or do the encryption methods take care of it? I am just getting into file input/output. I am just looking to make a simple console based one.
Create an a simple Payroll Management Application using the concept of Binary Tree. The program will allow you to add, sort, view, search record. The application have also the capability to save and retrieve data in a file.
I am trying to create a simple interface on console to allow to input some values to some variables. For ex:
int main() { double a = 1.5; double b = 2.5; double c = 3.5; string x;
[Code] ....
However, I want these three to display at the same time (now they display one by one), and in the console window I can move the cursor between input place of a, b and c with "arrow key" of keyboard.
How to perform RSA decryption with just the modulus and public exponent. I know that in RSA the private key does the decrypt, but thats not what I need to do. It is actually more of a verify used to recover information for the purposes of integrity (stupid I know) but its the problem I have to solve. Basically I need to do an RSA operation with the modulus and public key. When I try it I receive the error:
System.Security.Cryptography.CryptographicException: Key does not exist. at System.Security.Cryptography.CryptographicException.ThrowCryptographicException(Int32 hr) at System.Security.Cryptography.RSACryptoServiceProvider.DecryptKey(SafeKeyHandle pKeyContext, Byte[] pbEncryptedKey, Int32 cbEncryptedKey, Boolean fOAEP, ObjectHandleOnStack ohRetDecryptedKey) at System.Security.Cryptography.RSACryptoServiceProvider.Decrypt(Byte[] rgb, Boolean fOAEP) at IssuerPublicKeyRecoveryApp.Form1.PerformVerification() in C:devMarvinDevIssuerPublicKeyRecoveryAppIssuerPublicKeyRecoveryAppForm1.cs:line 543.
My Code is as follows: try{ //Create a new instance of RSACryptoServiceProvider. using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider()) { //Build the RSA key parameters to perform decrypt RSAParameters RSAKeyInfo = new RSAParameters();
[Code] ....
I have verified that my values are good on : [URL] ....
This example is strait off the MSDN website, and I realize it says that you need the private key information on the RSA import. For what I am doing, I do not have that, since I am doing a decrypt(not really). Since I know that the Math of an RSA operation is actually identical weather you are doing encrypt or decrypt, and it is just a convention of length for the exponent, I tried to do an Encrypt operation to decrypt the data, and the error checking caught that it was the wrong length in stead of performing the operation.
3. Write a program that reads a sequence of positive integers and prints out their sum, except that if the same number occurs several times consecutively, ignore all but the first. Assume an input of 0 marks the end of the input. For example, if the input is 3 8 5 5 4 9 1 1 1 1 8 0 then you should print 38 (i.e., ignore one of the 5's and three of the 1's).
How can decrypt the file that the program below encrypt?
// This program encrypts a file #include<iostream> #include<fstream> using namespace std; int main() { const int ENCRYPT=10; // amount to add to a chor const int SIZE= 255; // array size
my program is printing out a random symbol afterwards , when trying to copy a sequence of chars into a new buffer.
Code:
#include <stdio.h>#include <stdlib.h> int tokenCopy(char* dest, const char* src, int destSize); int main() { char buff[3]; int n = tokenCopy(buff, "This is a string", 3); printf("%d '%s' ", n, buff);
Code: #include <stdio.h> int main(){ double nc; for (nc = 0; getchar() != EOF; ++nc) ; printf("%.0f ", nc); }
It works well and I am using ctrl-D as my EOF. Now I understand that C is not really a language for dealing with text, which is why I am learning it more in depth, my degree was in robotics, and I think C is definitely the best place to be for me. So this may just be a quirk, but if I type more than 10 characters, I get the right answer from the program, however, if I type less than 10, for the sake of argument I type Hello and then return, if I at that point do ctrl-D, I get the answer 6D?
The 6 is right 5 letters and a return character, but what is the D?
I'm trying to write a program that detects deadlock. Some of the code I already tested in an earlier stage but at this point when I run the code it somehow gets stuck. I believe that it has something to do with a negative integer value. Anyhow, the program should still work if a negative integer comes up. Here's my code so far.
The program usually gets stuck after producing output displaying the "Available: " text. After that a list of tabbed numbers should appear, but it doesn't.
I decided to create a simple program to display a menu with options, while that is easy enough I had some difficulty when selecting an option that has options inside which also has an option again. While I had many issues in the past I'm finally finished with it and it works fine, but being new to programming and not knowing various other methods available.
Code: //:::::::::::::::::::::Simple Menu Program:::::::::::::::: //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
I have been working on a simple crc32 program in octave and have been using a program already done in C as a guideline. I have been having some problems since octave and C simply do things differently. Right now i have a problem with right shifting.
unsigned int crc = -85 unsigned int x = (crc >> 1);
The resulting x will be 2147483605. I tried putting 0xFFFFFFFF instead of -85 and i got the same result.
If i put -85 for crc in octave, i get a small number -43 which looks more reasonable.
The assignment is to write a program that statistically computes similarity of C syntax with another program; a same and a different. The one used here is in C language, it's called Battleship.cpp. The program must open a file and read line by line for keywords and then produce statistics. The reason my code is not running is the fopen function is failing and it goes to return -1. I am using MS Visual Studio 2013 and there are no compiler errors after turning off deprecation. I do see, however, this error UMEngx86.dll'. Cannot find or open the PDB file. The file being opened is in my source folder.
My program allows a server and a client to chat over a socket. Currently I have to wait for one of them to type a message and press enter, before a message from the other person can be received.
Is there a simple way for messages to be received instantly - but not disturb any message that is being typed in?
