Assume someone is exploiting DigitalNote, Dashcoin, or Bytecoin. Apparently, they could issue large amounts of those coins to manipulate that individual coin value. But what keeps them from exchanging this fictional value for other cryptos, and thus creating fictional demand for Monero and other coins? Also, do we know if these other cryptonote coins HAVE been exploited, yet? Should we be exploring attack-vectors from even state level attackers who might exploit one broken coin to devalue others?
2 Answers
Bytecoin was exploited shortly after its developers were privately notified of the bug. Most reasonable conclusion is the Bytecoin devs themselves performed the exploit. https://twitter.com/fluffyponyza/status/865619303651053568
But what keeps them from exchanging this fictional value for other cryptos, and thus creating fictional demand for Monero and other coins?
Free market and exchanges delisting them. If you try to sell infinite amount, you'd likely crash the price. Why would anyone buy it, knowing that anyone could create more out of thin air, is a mystery to me.
Also, do we know if these other cryptonote coins HAVE been exploited, yet?
Bytecoin has. See here. They patched the exploit but only after a certain block height so some offending transactions remained on the blockchain effectively inflating the supply for some fixed amount. Don't know if anyone bothered to check others.
Should we be exploring attack-vectors from even state level attackers who might exploit one broken coin to devalue others?
Who's "we"? It's an open-source world, anyone motivated can explore what he wants. Anyways, the question is too broad to give a meaningful answer.