It depends on what you mean by "reliably", but if you mean that the merchant has 100% confidence that they will get their money, the answer is no. The protocol just doesn't work that way.
It doesn't need to be 100 percent. But, factoring in criminal intent, can a merchant reliably process, say 999 out 1000 transactions reliably? I don't think merchants are going to be happier with less than that.