[drewbailey]

Ignorant question, do these kinds of challenges open up risk to someone being able to test the system, find vulnerabilities and then not disclose them so that they can be exploited when the election actually comes around?

[HaoZeke]

Yes and no.

The chances of only one person finding them reduces drastically, so even if someone wants to hide a flaw another might expose it...

If only to keep their credibility.