Encryption algorithms for product licensing

[Paul Aspinall]

Hi
Can anyone point me in the right direction to find some encryption routines
/ algorithms for use with product licensing??

I want to pull data such as the computer name etc etc, and encrypt them
against a string of mine, which will then create a product key.

Does anyone have a piece of code to do this, or any type of encryption that
may be useful in .NET

Thanks
Paul

[Andrea]

There are a lot of possibilities.

This is one of them.

Collect some informations (that rarely change) from client ex.: Computer
Name, Network MAC Address, ... and concatenate them into a string.
(ss="PCNAMEAB0F45DC")

Computete Hash Code:
System.Security.Cryptography.SHA1
h=System.Security.Cryptography.SHA1.Create();
byte[] bb=h.ComputeHash(System.Text.UnicodeEncoding.Unico de.GetBytes(ss));
Convert this binary result into hexadecimal string (323426534213423 ==>
XXXXXXXXXXXXXXXX).

Group into small piece if you want (XXXX-XXXX-XXXX-XXXX).

Andrea.

"Paul Aspinall" wrote:

Hi
Can anyone point me in the right direction to find some encryption routines
/ algorithms for use with product licensing??

I want to pull data such as the computer name etc etc, and encrypt them
against a string of mine, which will then create a product key.

Does anyone have a piece of code to do this, or any type of encryption that
may be useful in .NET

Thanks
Paul

[Pat A]

What do you mean by "encrypt them against a string of mine"? You are
going to provide a key (string) and use that to encrypt your data?
Where would that key be stored? In the binary? That's not too secure.

[grant]

You should think long and hard before you implement any form of
licensing youself that uses product activation (ie locks the license to
a single PC). Unless you have only a very few customers or else have
enough resources to offer 24/7 email and phone support then I would
look at some of the commercial products (xheo, xenocode etc) that do
this type of licensing and can provide that level of support.

Our company offers a simpler encrypted licensing solution because we
believe that product activation is actually a bad business model - see
our web page for the reasons why (www.infralution.com/licensing.html)

Regards
Grant Frisken