Compressible Encryption In PST File?
Apr 13, 2012
I would like to read the contents of an existing Outlook 2007 PST file by VB.Net. I find already the file and record structure, this is not a problem. But I have a problem with the compressible encryption how is used. Now I have read that this encryption is based on a simple byte-substitution cipher with a fixed substitution table. But unfortunately I can't find this table. Maybe someone can help me where to find this table or where I to find all the necessary information about compressible encryption.
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Feb 28, 2011
I'm having trouble writing the code to encrypt a file->networkstream->Decrypt the file.. I've tried several ways, but I keep failing....
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Jun 15, 2012
ive been trying to use System.Security.Cryptography to encrypt and decrypt a file but its not working for me
this code
Private Sub EncryptFile(ByVal sInputFilename As String, ByVal sOutputFilename As String, ByVal sKey As String)
Dim fsInput As New FileStream(sInputFilename, FileMode.Open, FileAccess.Read)
Dim fsEncrypted As New FileStream(sOutputFilename, FileMode.Create, FileAccess.Write)
Dim DES As New DESCryptoServiceProvider()
[code]....
called with
DecryptFile(OpenFileDialog1.FileName, SaveFileDialog1.FileName, "12345678")[/CODE]
outputs a file that is almost 2x as large as the source file that was encrypted.
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Aug 4, 2009
Imports System
Imports System.IO
Imports System.Security
Imports System.Security.Cryptography
[code]....
The above code is used by me to encrypt .avi files and it worked very well but the problem is that if the size of my video file is greater than 200 mb memory overflows probably as the code copy the whole input file into ram and then process it hence it put limitation of hardware,is there any better way to do it so that files > 200 mb could me encrypted in PCs with 1gb ram?
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Jul 13, 2011
I'm looking for advice/ideas in regards to ongoing file encryption.I have an event that fires frequently that contains small amounts of data passed through the eventargs.This data is then written out to disk (currently unencrypted).I need to encrypt this data (which, I can do).My attempt in the first five minutes was unencrypting the file, appending the data and reencrypting the file.This obviously works, but is pretty inefficient and not going to be my solution since the file could grow rather large and the resources to unecrypt/ encrypt grow larger as the file grows larger.My next thought was to encrypt each set of data as it's written out and have some kind of marker in the file to denote where to split so I could unencrypt each chunk to reproduce the original file.I'm leaning towards this approach now (though by encrypting small chunks of data multiple times, the file size will be considerably larger.As an example, if I encrypt each letter of the alphabet the file is approx 8 times larger than if I encrypted a string with all of the letters of the alphabet in this case each files decrypted content would be identitcal).
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Jun 16, 2011
1. How much load or data size our custom encryption/decryption algorithm can handle? E.g. what's the limit of file size that normal encryption/decryption algorithm supports.
2. What's the best way to use encryption while file transfer via internet?
3. Where and when encryption and decryption has to apply while uploading and downloading content from internet(Hosting on client or server machines)?
4. What type of algorithms suites for above approaches?
5. How much time it takes to encrypt / decrypt data for 10 MB, 100 MB, 1 GB etc
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Jul 12, 2011
I am trying to make a key that will be used in file encryption/decryption for my application. However, there is no user data involved with this application (As i would usually use the user's password to generate the encryption key), so i have to turn to another method.
I am thinking that maybe it is possible to generate a completely random key the first time the program runs, then save this key inside the program so that it is inaccessible by the user. The user will not be shown this key, but the key MUST be randomly generated for each application, and it also must stay constant once it is created.
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Jun 21, 2011
I have set up a method in vb.net and in xcode for encrypting a string using as far as i can tell the same parameters for an AES encryption.I've looked all over the place but cannot find information on whether they use the same encryption algorithm and settings.
this is the vb.net code:
Dim encryptAES As New AesCryptoServiceProvider()
Dim encoding As New UTF8Encoding()
Dim encryptor As ICryptoTransform
encryptAES.Key = encoding.GetBytes("12345678901234567890123456789032")
encryptAES.IV = encoding.GetBytes("1234567890123416")
encryptAES.Mode = CipherMode.CBC
[Code]...
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Oct 1, 2011
I use the following Rijndael code to do encryption without fail for many times. But why it can not encrypt an ISO file with 4.2 GB? In fact my computer has 16GB memory and it should not be a memory problem. I use Windows 7 Ultimate. The code is compiled as winform (.Net 4) using Visual Studio 2010 (a VB.NET project).
I have checked that the ISO file is OK and can be mounted as virtual drive and even can be burnt to DVD rom. So it is not the ISO file problem.My question: Why the following code cannot encrypt an ISO file with size of 4.2GB? Is that caused by the limitation of Windows/.NET 4 implementation?
[Code]...
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Feb 10, 2011
What I've decided to start working on is pretty much a personal project but something I may use in my UNI course in due time. I'm creating a security program with a set of access codes (yes I am a bit of a star trek fan) - 4 in total to be exact. I want to be able to use an Encrypted key file in form of a simple notepad created text file to update the codes at any due time. All I'm looking to do is write the access codes to the text file (say for a friend to use the program), Encrypt the file through the program and be able to also decrypt to obtain the new access codes on demand also via the same program. Once decrypted the codes can be read and verified if the user has entered each one correctly. I could hard code the access codes into the program but would rather do it the way I've thought of.
Back in the days of the old VB6 there was a simple method but for some reason that doesnt work any more. What I guess I'm looking to do is have 4 text fields where 4 digit access codes are typed into, have the program take them and encrypt each one is then written to the text file. Hoping that will make it a bit clearer what I'm trying to achieve as I think I made it sound like I want to encrypt the text file after the info has been written to it, which is of course one option so wouldn't mind know how to do that too!
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Feb 16, 2010
I'm working on a basic file encryption by using the Imports System.Security.Cryptography.I was thinking of putting a password as a final security measure.Would i have to store the password inside the file or how will this work?
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Dec 19, 2011
I recently changed application settings to be in an encrypted config file.The first time I run any application and try to retrieve a setting (My.settings. ...) from the config file I get an Unrecognized attribute 'configProtectionProvider'If I restart the application I don't get an error due to the fact that it doesn't re-encrypt during that run. Why when I run the application for the first time am I getting this error?
I am encrypting the config file on application startup using the following code:
[Code]...
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Apr 22, 2011
I recently made a simple pseudo-encryption program that changes each character into another. It is capable of encrypting and decrypting a string. This can also be done to any text file as well. The characters range from ASCII 32-254 (This on it's own may be an issue because of #127 being DEL).
Because I believed my own coding may be at fault, I attempted this with Triple Des with identical results.For Triple Des, the requirements for en/decryption was:
Encrypt: String to Byte
Decrypt: Byte to String
And to change them either direction, I used UTF8. I also attempted ASCII and UTF32, but I don't know what I should do. I am considering dropping this but I want to learn problems like this because I am currently in college and haven't started my core classes for programming yet and want the head start.
The point where I have come into a problem is attempting to do this to another file type like an image. I looked at the results from encrypting then decrypting and the results were similar, but it seems file encoding must be the culprit.
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Sep 29, 2011
I'm creating a Rijndael file encryption application. I will using a unique IV for each file encryption.
My question: Where is the proper place to embed the IV info?
My initial thought is to append it at the end of the file's content. Is that a good choice?
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Mar 25, 2012
is there anyway that I can convert this to use RSA encryption?
Imports System.Text
Imports System.Security.Cryptography
Imports System.IO
Public Class ClsEncryption
[code].....
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Jan 28, 2011
I have been trying to create an app that will do xor encryption. I have tried a few different functions but none of them seem to give me what I want. I need it to put the coded text into a 7 bit ascii string. For example if the key was a - 1100001 and the text to be encrypted was s - 1110011 then it would return 0010010 as the encryption. One of the pieces of code I tried to use
Public Function XOREncryption(ByVal CodeKey As String, ByVal DataIn As String) As String
Dim lonDataPtr As Long
Dim strDataOut As String
Dim temp As Integer
[code]....
This returns a hex digit though which will not work for what I want.
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Sep 3, 2009
have made a library for my vb.net project by combining 3 libraries (using ilmerge).
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Nov 15, 2011
I am attempting to create a program that can do raw RSA encryption (performing the encryption without using 'Encrypt' and 'Decrypt') of a user's message that can contain a-z, A-Z, 0-9, and [,.;:'"()]. I've attached a screen shot of the application form.
Basically, the user will pick from a list of prime numbers from the first box and input them into p and q. They will type their message in the designated textbox and then hit <encrypt> which will encrypt using p and q and then show the encrypted message below. I'll leave out the Key box since that deals with the math behind the encryption.
The part I am stuck on right now is assigning a number to each one of the characters so that it can be encrypted. These numbers need to remain the same so that the message can be decrypted as well.
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Nov 23, 2010
i have this .xml file read and display at runtime by vb.net2003. the .xml file is the database which contain various data and its not for adding more data or edited by user so i need to protect the file so that my code can read and display those data. can anyone know how to protect the file.
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Feb 1, 2012
Here is some code that works well for strings:
[Code]....
modifying these functions to encrypt/decrypt byte arrays rather than strings. Also, to have the functions return the encrypted/decrypted byte array, rather than a string.
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Oct 12, 2011
I am trying to implement the encryption script from Barclays payment gateway, however it's in VB and the rest of our site is in c#.
The script is
Public Class Example
Inherits System.Web.UI.Page
#Region " Web Form Designer Generated Code "
[code]....
How am I able to either run this VB in my C# aspx page? Or do I need to convert it to use c#?? In my aspx page, I have the first line
<%@ Page Language="C#" ContentType="text/html" ResponseEncoding="utf-8" CodeBehind="encryption.cs" %>
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Jun 2, 2009
my program takes a txt file and encrypts it successfully but it returns the wrong thing when decryting.[code]
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Sep 23, 2010
I have a problem with an encryption made in AdobeFlex and which I need to translate to VB.NET.The core is a AES Encryption, but I tried several ways and code and the encrypted strings weren't the same The original Flex Sourcecode is:
VB
private function encryptAES(arg1:String, arg2:String, arg3:String="aes128-cfb8", arg4:String="None"):String
{
var loc1:*=com.hurlant.util.Hex.toArray(com.hurlant.util.Hex.fromString(arg2));
[code]....
My question is how to get the code work in VB.NET
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May 30, 2011
I have a problem with an MD5-hash algorythm that's acting very oddly.Here's the
vbcode
Imports System.Security.Cryptography
Imports System.Text
[code].....
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Aug 10, 2009
I'm looking to use RSA Asymmetric encryption to encrypt some data. I've read this article on the forums with a similar title, but it did not answer my question. What I would like to do is use the private key of an RSA key combination to encrypt (sign?) the data and use the public key to decrypt (verify?), as per this wikipedia article . I would like to use this method because I want people to be able to read the data, but not create it themselves. I've copied the code from Peter Bromberg's article RSA Encryption in .NET Demystified , but always get an exception with the "Bad Key" message. If I use the public key for decryption, it works fine (the opposite of what I want). use the public key for encryption.
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Oct 20, 2011
In my database I have a column that contains the passwords, and I use the
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Aug 21, 2009
How would I be able to use my own Encryption Algorithm in my program such as encrypting text. I havn't been able to figure this out.
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Apr 19, 2012
i have in php two functions, one to encrypt and one to decrypt.
PHP
function Encrypt($message) {$Method = "AES-256-CBC";$passPhrase = "key";$iVector = 1234567890123456;$encryptedMessage = openssl_encrypt($message, $Method, $passPhrase, $iVector);return $encryptedMessage;}function Decrypt($message) {$Method = "AES-256-CBC";$passPhrase = "key";$iVector = 1234567890123456;$decryptedMessage = openssl_decrypt($message, $Method, $passPhrase, $iVector);return $decryptedMessage;}
what i want to do, is encrypt a message, using the same method in vb.net as i do in php, how would i go about doing this?
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Aug 9, 2009
I've seen a lot of threads on the web discussing about which encryption algorithm is better.According to what I've read, AES encryption algorithm is based on Rijndael's algorithm, and the first is the one being implemented by the US's government to secure TOP SECRET files.From what I've tried RijndaelManaged only supports 128bit long keys (that would be a byte array with 16 byte values, right?) and not 256 as I had first thought; however, AES seems to support 256bit keys (or is it all the way around?), I haven't personally tried DES nor TripleDES.
So, which one is better or more secure? And what's up with asymmetrical encryption? What's the difference? Can both symmetrical and asymmetrical encryption be used for the same thing?
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Sep 12, 2011
At first i thought it was the padding since mcrypt uses zero padding but i changed the php to use PKCS7 and get the same exact results.I think it has something to do with the padding in the php.Test output from .Net:
Key: d88f92e4fa27f6d45b49446c7fc76976
Text: Testing123
Encrypted: /DMkj7BL9Eu2LMxKhdGT+A==[code]......
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