How does due diligence work for a startup's technology?

Suppose the main value of a startup is a breakthrough technology. It has no revenue, no customers besides early adopters and is purely living off VC funding at the moment to keep the research effort going.

Now a large corporation wants to acquire the startup. The corporation requested a detailed breakdown of how the technology is created and calls it a standard tech due diligence before writing a check.

From the startup's point of view, after revealing the details, the cooperation could duplicate the technology with their own engineers. Even though the startup might have patents pending for protection, it does not have the money to hire lawyers and play the litigation game.

From the corporation's point of view, it's natural wanting to make sure what they are really paying for.

What is the typical process of tech due diligence for a startup acquisition that protects both the buyer and the startup?