need some advice on creating unlock codes for apps

[Milsnips]

hi there,

i would like some pointers in how to go about creating some kind of serial
unlock code based on hardware key i create generated from the pocketpc?

any help appreciated,
Paul

 

[Roland Dick]

Hi Milsnips,

maybe you want some kind of asymmetric encryption? For example:
- User sends hardware key to you
- You encrypt the hardware key with your private key and send the result
to the user
- User (your app) decrypts the cipher text with a public key and
compares against the hardware key

For asymmetric encryption, OpenNETCF.org has some classes for you.

Kind Regards,

Roland