A cryptocurrency backed by oil would be a big first. A cryptocurrency backed by a sovereign government would be even bigger.

But while Venezuela claims it is going to do both very soon with the petro, experts are doubtful the country has the capabilities or the characteristics to achieve its goal.

The petro will be dogged by a major question, "Is it redeemable, in other words, can you take physical delivery?" notes finance professor Stephen McKeon of the University of Oregon.

The strength of any currency backed by a commodity, regardless of whether it is physical or digital, is that holders must believe they can exchange it for the actual commodity. When the U.S. was on the gold standard, individuals could bring their dollars to a bank and exchange them for physical gold.

Venezuelan President Nicolas Maduro says each petro will be worth the equivalent of one barrel of oil, and he has specifically designated the oil from field one of the Ayacucho block in the Orinoco region of Venezuela, which contains more than 5 billion barrels.

But McKeon says Venezuela carries a lot of "counterparty risk" because it has little rule of law and falling oil production. If Venezuela fails to deliver the oil, he asks, what is the legal recourse for holders?

Joshua Satten, blockchain partner at Wipro, also questions whether Venezuela is a "sound enough government" to instill confidence in would-be miners and holders of the petro.