"One of the first things anyone learns about Zcash" is that at least one of the ceremony's participants must be trusted to have securely destroyed his toxic waste.
This article is about the fact that there could be a backdoor, whose absence can only be proven by revealing all participants' toxic waste.
You'll note that these two things are at odds with each other.
Not sure why this isn't mentioned in the article.
> This article is about the fact that there could be a backdoor, whose absence can only be proven by revealing all participants' toxic waste.
This is incorrect, as stated above. Instead of revealing their toxic waste, we reveal proofs-of-knowledge so we can use pairings to ensure the parameters encode the circuit correctly.
I still learned something "new" from the article, I was only aware of the ceremony issue that "everbody knows" of.