Write A Program To Decrypt And Encrypt Ceaser Cipher Or Ceaser Shift
Sep 7, 2009
I am trying to write a program to decrypt and encrypt the ceaser cipher or ceaser shift (which ever you prefer using), and I really need help I don't even know how to start. I am hoping that someone on here can atleast help me to get started with writing the program.
I want to make a program to encrypt and decrypt messages using a word cipher or random lettering(no duplicate letters) etc.
I've got 2 input boxes: input text and keyword box Two Buttons: encrypt and decrypt
This is about all I have coded so far
Code: Private Sub Encrypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Encrypt.Click Dim EncryptInput As String
[Code]....
I have a few guess how to do this (not 100%) but setting up some sort of array might be one (not sure if it's the easiest)
Edit: one thing for sure I want to be able to separate the characters in the keyword into the start of an array (if the array is the best option)
I don't necessarily need code, I just need some advisement on how to approach this with commands. I don't know too many commands (only remember some fortran)
I am trying to encrypt text to a textfile(.txt) and then decrypt it in a diff. program.The encrypting part works fine.I have tried these functions in a textbox and they work perfectly, I get InvalidCastException when trying to decrypt from the .txt file.
I've written an encryption program that encrypts and decrypts selected files using a user-entered password as the encryption key.
Once en/decrypted, the user will be asked if they want to delete the file that was used, and, in the case of decryption, open the newly decrypted file.
My brother came up with an idea for this application yesterday that might save me a lot of grief should I forget a password. [code]...
Need to design a program that can encrypt and decrypt messages stored in simple text files using a private key stored in a separate file. Software should also be able to allow the users to enter simple messages that either displays the encrypted or decrypted message. The encryption method should use a simple substitution method. It should be set out in the following format:
Example (the "@" is the separator):
@ The character The Code End of line A @ 4gh EOL B @ 84!9 EOL
Has to use the 256 ASCII character codes. The separator will be used to separate the character and its corresponding code.Here are the pseudocodes I have come up with:
� Read any private key file separator = readline(file); while not EOF(file) do tempStr = readline(file);
Vigenere Cipher which I am trying to code in VB.Net. The main thing is to decrypt to plain text with keys provided. Currently, I did a small code to decrypt NIOZS to COMPU with the key LUCKY. This is done by storing the cipher text, the key text and the English alphabets in 3 different arrays each starting at index 0.
However, I do not know how to proceed on if my cipher text is longer. My cipher text file consists of texts in .txt, every 5 words are group together (e.g. NIOZS ECPQE TOGCG YMKQF E). The keys are all different in lengths. I also understand about checking letter frequency to deduce the key but I do not know from which point to start on.
Can anyone give me some pointers as to how I can get to start for my program? I tried looking for samples but some applets on the web wasn't exactly accurate or I can't start it up after I dl-ed.
I have a classic ASP page which constructed a querystring for a link to an ASP.NET page. Certain elements in the querystring are somewhat sensitive so I want to encrypt them. I've come across some techniques for doing this in ASP.NET and also in classic ASP but I'm not sure how to do it from classic ASP to ASP.NET. I'm using .NET 3.5.
i need a standard way of encrypting a string and decrypting it using AES. I am aware of the Cryptography class, however almost every example creates a class to do the encryption,If .Net already has this implemented and ready to use why would we create classes for encryption and decryption, isn't it as simple as calling the encrypt method of the class or decrpyt and passing in the text. Unless everyone is wanting to centralize the code. But even then i see so many different examples from File,Data Protection etc..
I need some help on saving/reading xml from/to dataset. I would like to make that complete file is encrypted and not only some elements inside or part of file.Currently this is not working in any way at all.[code]
I ended up getting this properly working, as far as encrypting a file goes:How to encrypt and decrypt a file by using Visual Basic .NET or Visual Basic 2005 However, the catch is I have to change the name of the output file. What I was hoping to do is overwrite the original with the encrypted file, but when I tried that on a large file, it ended up only getting about 8 bytes of it.
Does anybody have any suggestions or recommendations? The overall idea is that I want to keep a file encrypted until it needs to be unencrypted for use by a program, but I'm not sure if there are better tools out there or if there's a better way of accomplishing this.
Question 2: I would really, really like to encrypt an entire folder, which I'm guessing would be faster than file by file, but when I try I keep getting access denied errors, even with DOS Cipher. Is there a way to do this with a key?
I am using vb.net 2008 i want to Know how can i encrypt text in a text box save it to a file then read the file decrypt the text and finaly display it in text box .
I am trying to encrypt a zip in VB.NET to send to an android device using Air. Then once its on the device, decrypt it using the key and IV.
Here is part of my VB.NET Code:
Private Sub EncryptBytes(ByVal fileIn As String, ByVal fileOut As String, ByVal pass As String, ByVal ivString As String) Dim crypt As New RijndaelManaged crypt.KeySize = 256
[Code]...
This is not working ... Note that I tried to write a PKCS7 class based on a Java class I found. The hurlant package I downloaded only had PKCS5. VB.NET did not provide any of the same padding classes as hurlant comes with. I wish I could using "None" but I couldn't get passed the error in VB.I think there may also be an issue with the way I am converting a string into a byte array in VB vs Air.
how to encrypt / decrypt a string in VB.Net.I followed the example given here and wrote the following code (below). There's a text box, an "encrypt" button, and a "decrypt" button. The idea is to type something into the text box ("like 'hello world'"), click "encrypt", and see the encrypted version appear in the text box. Clicking "decrypt" should then take you back to the original string.
But when I try to encrypt I get an error when I try to "FlushFinalBlock". The error is: "Length of the data to encrypt is invalid".The "decrypt" part is a total shot in the dark, as the example quoted above only deals with encryption, not decryption. I'm sure it's wrong, but since I can't get "encrypt" to work I haven't tested it yet.
Imports System.Data.SqlClient Imports System.IO Imports System.Security.Cryptography Public Class Form1
I just know it works. So as a personal project I'm trying to learn in VB/C# all about Cryptographic methods and how to use those techniques to encrypt and decrypt files. [code]
i have found a few encrypt/decrypt tutorials online but either they dont work or they only work when the application is running so if i encrypt a string using some code i find and save it (in its encrypted form) and then restart the application and enter the saved encrypted string into a textbox and run the decrypt code it wont decrypt it. i don't understand why en/de-cryption is so hard or why there are so little working examples online. could someone be so kind and show me some code that can let me en/de-crypt a string even if i restart the application or use it on a different computer? and doesn't show the weak key errors all the time.
I am interested in knowing if non-text files like .xls/.xlsx or .doc files can be encrypted... From the Devlopers Guide on MSDN, I found code snippets that allow encryption / decryption of .txt files. This works absolutely fine. However, I would like to know if similar procedure can be used to encrypt/decrypt file other than .txt file.
I am looking for any good tutorial about like in subject of this topic, how to up more secure my application. What I need is to the solution to encrypt my queries in application. Is there any good tutorial or something you could propose me?
What are the best way to encrypt and decrypt stream of data ?I would like that my program read a file.. and unencrypt it in memory then when it save it.. it encrpyt the stream and save it.
I have created a encryptor/decryptor that allows you to encrypt/decrypt text in a textbox, or a file. The basis of the system is to allow a user to thoroughly protect data within their system. Is there anyone that would be willing to test the program?
For my VB assignment I need to encrypt message and decrypt it again I managed to do it all pretty easily but the problem is the enter key. How can I turn it into ASCI and back again example
user entered - Hello My Name is kurt encrypted Message - Hello13My Name is kurt Decrypted Messafe - Hello My Name is kurt
The Space is no problem I managed to encrypted well but the enterkey is coming wrong (btw 13 because its the asci value for enter key).
I save data from datagridview to text file . I also load the same data from text file into datagridview for edit and update the same thing to text file. Now i want to make my Drill layer header.txt in encrypted format to prevent anyone to open that file and modify out of program. They only can modify it through the program How can we do like this?
This code can encryp the text file. But accrding to this code EncryptFile("c:\Drill Layer Header.txt", _ "c:\Drill Layer Header original1.txt", _ sSecretKey) It ask for input and output file. So it take data from Drill Layer Header then encrypt the save in drill layer header original.txt. I want it to take data from drill layer header and encrypt and save in same file.
I use these code to encrypt any plain text in vb2008.I want decrypt and use generated file in my app in android.I know that put files in assets folder and i use it.this code use Cryptography to encryption.how i can decrypt generated files in my android app.and how i use them in my android app.
Imports System.Security.Cryptography Public NotInheritable Class Simple3Des Private TripleDes As New TripleDESCryptoServiceProvider
this code is in a VB 2008 program which I inherited. The below code compiles perfectly but I haven't been able to figure out how to execute it!What code goes in the EncryptDialog_Load which will execute the Encrypt and then the Decrypt functions, then how I send and collect the key() and IV() information using this new code?
Code: Imports System Imports System.IO Imports System.Xml
I have two functions that are supposed to encrypt and decrypt a string but the encrypt function returns a different encrypted string for the same text everytime. What have I done wrong?