How to generate product keys after an order This article will show you how to generate product keys and send them to your users using the LimeLM web API. At the end of this tutorial you'll have a payment form that automates the entire order process. Hi, i have Developed an Application in vb.net. For this,i have to Generate a license Key Based on Cpu id, mother Board Id, and Mac Address. I tried this. But When i Encrypt this Three Values,i got.

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Creating and managing keys is an important part of the cryptographic process. Symmetric algorithms require the creation of a key and an initialization vector (IV). The key must be kept secret from anyone who should not decrypt your data. The IV does not have to be secret, but should be changed for each session. Asymmetric algorithms require the creation of a public key and a private key. The public key can be made public to anyone, while the private key must known only by the party who will decrypt the data encrypted with the public key. This section describes how to generate and manage keys for both symmetric and asymmetric algorithms.

Symmetric Keys

The symmetric encryption classes supplied by the .NET Framework require a key and a new initialization vector (IV) to encrypt and decrypt data. Whenever you create a new instance of one of the managed symmetric cryptographic classes using the parameterless constructor, a new key and IV are automatically created. Anyone that you allow to decrypt your data must possess the same key and IV and use the same algorithm. Generally, a new key and IV should be created for every session, and neither the key nor IV should be stored for use in a later session.

To communicate a symmetric key and IV to a remote party, you would usually encrypt the symmetric key by using asymmetric encryption. Sending the key across an insecure network without encrypting it is unsafe, because anyone who intercepts the key and IV can then decrypt your data. For more information about exchanging data by using encryption, see Creating a Cryptographic Scheme.

The following example shows the creation of a new instance of the TripleDESCryptoServiceProvider class that implements the TripleDES algorithm.

When the previous code is executed, a new key and IV are generated and placed in the Key and IV properties, respectively.

Sometimes you might need to generate multiple keys. In this situation, you can create a new instance of a class that implements a symmetric algorithm and then create a new key and IV by calling the GenerateKey and GenerateIV methods. The following code example illustrates how to create new keys and IVs after a new instance of the symmetric cryptographic class has been made.

When the previous code is executed, a key and IV are generated when the new instance of TripleDESCryptoServiceProvider is made. Another key and IV are created when the GenerateKey and GenerateIV methods are called.

Asymmetric Keys

The .NET Framework provides the RSACryptoServiceProvider and DSACryptoServiceProvider classes for asymmetric encryption. These classes create a public/private key pair when you use the parameterless constructor to create a new instance. Asymmetric keys can be either stored for use in multiple sessions or generated for one session only. While the public key can be made generally available, the private key should be closely guarded.

A public/private key pair is generated whenever a new instance of an asymmetric algorithm class is created. After a new instance of the class is created, the key information can be extracted using one of two methods:

  • The ToXmlString method, which returns an XML representation of the key information.

  • The ExportParameters method, which returns an RSAParameters structure that holds the key information. Citron id card generator 2.0 product key.

Both methods accept a Boolean value that indicates whether to return only the public key information or to return both the public-key and the private-key information. An RSACryptoServiceProvider class can be initialized to the value of an RSAParameters structure by using the ImportParameters method.

License Key Generator

Asymmetric private keys should never be stored verbatim or in plain text on the local computer. If you need to store a private key, you should use a key container. For more on how to store a private key in a key container, see How to: Store Asymmetric Keys in a Key Container.

The following code example creates a new instance of the RSACryptoServiceProvider class, creating a public/private key pair, and saves the public key information to an RSAParameters structure.

Generate License Key Vb.net Code

See also

Generate License Key Vb.net File

P: n/a
Newbie Coder wrote:
Almost weekly the same question is asked in this newsgroup & you'll get
pointed to the same few controls like the ASPOSE one by the MVP's
Doesn't anyone write there own one of do like the MVP's & search Google for
the answer?
There are problems with simply supplying code samples for what the OP is
seeking -
1. To provide the functionality required needs much more than a code
snippet, it usually requires an entire application to show how you might
do it.
2. Showing someone's solution may pose a risk of exposing
Code/Algorithms that people have spent a long time perfecting and don't
want to become public knowledge. (For obvious reasons).
Nonetheless, I HAVE provided details in earlier posts, and do so again
now, in hope that the OP will obtain some inspiration to develop his/her
own -
(Sample of my Code that uses the Serial Number of the HDD as part of the
Application Serial Number)
*******
I use the following code (watch for wrapping!) -
Imports System.Management
'' <summary>
'' String of 1 to 2 chars. eg. 'C' or 'C:'.
'' </summary>
'' <param name='sDriveLetter'></param>
'' <returns></returns>
'' <remarks></remarks>
Public Function GetDriveSerialNumber(ByVal sDriveLetter As String) As String
If Len(sDriveLetter) = 1 Then
sDriveLetter &= ':'
Else
sDriveLetter = Strings.Left(Environment.SystemDirectory, 2)
End If
Dim HardDiskInfo As New ManagementObject('Win32_LogicalDisk.DeviceID='
& ChrW(34) & sDriveLetter & ChrW(34))
Dim HardDiskProperty As PropertyData =
HardDiskInfo.Properties('VolumeSerialNumber')
Return HardDiskProperty.Value.ToString
End Function
I first obtain the Drive Serial Number and then ensure it is
8-Characters in length -
Dim sA As String =
GetDriveSerialNumber(Strings.Left(Environment.Syst emDirectory, 2))
Dim N As UInt16 = Len(sA)
If N < 8 Then
sA = sA.PadRight(8 - N, '0')
ElseIf N 8 Then
sA = Strings.Left(sA, 8) 'Truncate to 8 Chars.
End If
After this I 'AND' the value with another routine that automatically
generates an 8-Character HEX number based on the title of my software.
I then end up with a 16-Character HEX number, which is unique to each of
my applications and unique on every computer, I then do some more
XOR'ing and present this to the User as the Application Serial Number.
I obviously have another application that reverses all of this to
provide an Unlock Code that the User enters.
There are literally hundreds of Users running my applications using this
method, and although it really only stops the honest pirates, it serves
my purposes well.
If you'd like to see an example, please download one of my apps (written
for specific clients) from the following site -
http://www.arnfieldcomputerservices..di/publish.htm
This will provide an example of what my Registration Screen looks like.
If you require any further assistance, please feel free to contact me
direct via the email address used in this post.
*******
FootNote: When this code sample was last posted, I received warnings
from others that not all systems have drives with Serial Numbers. I
don't dispute this (although I've NEVER seen it) so you might want to
consider an additional or an alternative means of obtaining a unique
number from the system. (ie. MAC Address etc.)
ShaneO
There are 10 kinds of people - Those who understand Binary and those who
don't.