There is one more idea I want to share.
If there is a bot owner who can produce a viable solution for every possible starting block that fit in say 60 sec threshold and require less than 60 sec for this... then this botowner is now probably building an alternate blockchain fork from 8000 block. And he will publish this blockchain shortly. His blockchain will be longer than the current blockchain because he can catch it up very quickly. If he can produce a solution in 5 sec then he needs a 5000 * 5 sec ~ 7 hours to produce a chain of 5000 blocks with solutions close to 60secs. Motocoin network will accept his new chain because his chain will be longer than the current one and it is done. This is not a 51% attack this is something different because attacker do not even need a lot of computation power to achieve this.
This is precisely the same as a 51% attack. To do it (probabilistic) successfully you would need to not only be mining your new chain to catch up, but also keeping up with the real chain's pace of new production as well, so you need to have above 50% of the total hashing strength on the network. (the hashing strength to keep your chain in pace with the rest of the network as a whole, plus some extra to get ahead.) This is still not different from the first fpga and GPU miners and later the early asic miners on BTC.
I could produce blocks well above 1 per 5 seconds, but why? It would not be worth the energy spend to grab the couple of bucks on the buy side of the books, and it would certainly destroy the coin and any hopes of getting more than that in the future. For anyone with the hashing strength the rational thing to do is just mine the coin normally to secure and strengthen the network and collect the subsidy.
In other words. A bot owners can produce a blockchain fork as long as they want, each block in the forked chain will contain a solution close to 60sec. Bot owner needs far less time to achieve this than the sum of the thresholds for blocks in the chain itself.
I'm not sure I follow you. How would this be different from any other coin, where someone holding an overwhelming majority of the hashing strength can rewrite tx history at will to a depth relative to their network dominance?
An actual block computation complexity is not connected to the threshold itself.
I think I've already beaten this horse to death, but they are directly connected. Finding "any path that makes it to the coin" is quite a bit easier than finding a path that makes it to the coin with a target near the minimum bound on run time, for both bots and humans. Try it yourself in ForFun mode.
This compromise the main idea of a blockchain. A blockchain fork attack complexity is very low now.
No, fork attack complexity is only very low right now. It is, however, much higher than it was a week ago, and will be much higher next week, and so on. This, too, is true of any successful crypto where difficulty increases steadily.
Motocoin is literally compromised now. I am out.
It is only compromised in the same way that the first FPGA and GPU miners "compromised" bitcoin, which is to say basically not at all in the long run.