I hope you do realize that it's an old article.
That's the problem. Because it has been known for some time, exploits exist.
I am software developer but I do not understand enough of cryptography to understand whether the article is relevant.
I just saw that our coin was attacked a few days ago. Someone has generated transactions with 1,000,000 fee.
You have to ask yourself how this is possible and if there are other gaps in the core.
This coin is a monero fork isn't it? If so, then it all comes down to the date dev forked the code. If that date is after 21/02/2017 then it's all good as monero devs patched the bug that day.