I Nadya

I think there is another issue;

1)Craig's method is great except it requires to read a data file for the last key. In a large network environment this can become slow as each user needs to access the file for their keys.

2)If the application is running in a data capture heavy environment this creates additional network traffic.

3)The fact that its in a file creates the danger of what can happen to the file in respect of corruption, loss, or tampering?

In my example (and there are other variations of it) it creates no network traffic, no danger of corruption, and tampering can only be done by changing the exe itself. The entire key is generated locally. And as mentioned you can reduce total key size in a variety of ways.

I believe that the code for getting the hard disk serial number is available under the download section of UT. It uses 3 functions all in Win32API. They are GetDriveType, GetLogicalDrives, GetVolumeInformation.