Can i crack usb security dongle?

I have to develop a plugin for a program that uses dongle to activate.Just wondering can i crack the key of the usb or something else?

I'm sure you can, but you might be running afoul of the various legislation regarding the act of reverse engineering content protection systems. I am, of course, referring to the American DCMA statues.

In any event, as pure thought experiment, I might try the following:

• Clone the USB firmware image, and load it into a virtual USB port
• As you say, crack the key and the USB interface, and short-circuit the check in a virtual USB device.
• Locate the part of the code in the program that is doing the security check, and edit the bytecode / machine code to return successful without actually looking for the device.

NOTE: Do not contact me for services related to defeating security systems. I won't do it, and I'll probably lecture you.