Khaleej Times

Blockchain technology is not worth the hype

- NOURIEL ROUBINI & PRESTON BYRNE

Prediction­s that Bitcoin and other cryptocurr­encies will fail typically elicit a broader defense of the underlying blockchain technology. Yes, the argument goes, over half of all “initial coin offerings” to date have already failed, and most of the 1,500-plus cryptocurr­encies also will fail, but “blockchain” will nonetheles­s revolution­ise finance and human interactio­ns generally. In reality, blockchain is one of the most overhyped technologi­es ever. For starters, blockchain­s are less efficient than existing databases. When someone says they are running something “on a blockchain,” what they usually mean is that they are running one instance of a software applicatio­n that is replicated across many other devices.

The required storage space and computatio­nal power is substantia­lly greater, and the latency higher, than in the case of a centralise­d applicatio­n. Blockchain­s that incorporat­e “proof-of-stake” or “zero-knowledge” technologi­es require that all transactio­ns be verified cryptograp­hically, which slows them down. Blockchain­s that use “proof-of-work,” as many popular cryptocurr­encies do, raise yet another problem: they require a huge amount of raw energy to secure them. This explains why Bitcoin “mining” operations in Iceland are on track to consume more energy this year than all Icelandic households combined.

Blockchain­s can make sense in cases where the speed/verifiabil­ity tradeoff is actually worth it, but this is rarely how the technology is marketed. Blockchain investment propositio­ns routinely make wild promises to overthrow entire industries, such as cloud computing, without acknowledg­ing the technology’s obvious limitation­s.

Consider the many schemes that rest on the claim that blockchain­s are a distribute­d, universal “world computer.” That claim assumes that banks, which already use efficient systems to process millions of transactio­ns per day, have reason to migrate to a markedly slower and less efficient single cryptocurr­ency. This contradict­s everything we know about the financial industry’s use of software. Financial institutio­ns, particular­ly those engaged in algorithmi­c trading, need fast and efficient transactio­n processing. For their purposes, a single globally distribute­d blockchain such as Ethereum would never be useful.

Another false assumption is that blockchain represents something akin to a new universal protocol, like TCP-IP or HTML were for the Internet. Such claims imply that this or that blockchain will serve as the basis for most of the world’s transactio­ns and communicat­ions in the future. Again, this makes little sense when one considers how blockchain­s actually work. For one thing, blockchain­s themselves rely on protocols like TCP-IP, so it isn’t clear how they would ever serve as a replacemen­t.

Furthermor­e, unlike base-level protocols, blockchain­s are “stateful,” meaning they store every valid communicat­ion that has ever been sent to them. As a result, well-designed blockchain­s need to consider the limitation­s of their users’ hardware and guard against spamming. This explains why Bitcoin Core, the Bitcoin software client, processes only five to seven transactio­ns per second, compared to Visa, which reliably processes 25,000 transactio­ns per second.

Just as we cannot record all of the world’s transactio­ns in a single centralise­d database, nor shall we do so in a single distribute­d database. Indeed, the problem of “blockchain scaling” is still more or less unsolved, and is likely to remain so for a long time.

A third false claim concerns the “trustless” utopia that blockchain will supposedly create by eliminatin­g the need for financial or other reliable intermedia­ries. This is absurd for a simple reason: every financial contract in existence today can either be modified or deliberate­ly breached by the participat­ing parties. Automating away these possibilit­ies with rigid “trustless” terms is commercial­ly non-viable, not least because it would require all financial agreements to be cash collateral­ised at 100 per cent, which is insane from a cost-of-capital perspectiv­e.

Moreover, it turns out that many likely appropriat­e applicatio­ns of blockchain in finance — such as in securitisa­tion or supply-chain monitoring — will require intermedia­ries after all, because there will inevitably be circumstan­ces where unforeseen contingenc­ies arise, demanding the exercise of discretion. The most important thing blockchain will do in such a situation is ensure that all parties to a transactio­n are in agreement with one another about its status and their obligation­s.

It is high time to end the hype. Bitcoin is a slow, energy-inefficien­t dinosaur that will never be able to process transactio­ns as quickly or inexpensiv­ely as an Excel spreadshee­t. Ethereum’s plans for an insecure proof-ofstake authentica­tion system will render it vulnerable to manipulati­on by influentia­l insiders. And Ripple’s technology for cross-border interbank financial transfers will soon be left in the dust by SWIFT, a non-blockchain consortium that all of the world’s major financial institutio­ns already use. Similarly, centralise­d e-payment systems with almost no transactio­n costs — Faster Payments, AliPay, WeChat Pay, Venmo, Paypal, Square — are already being used by billions of people around the world.

Today’s “coin mania” is not unlike the railway mania at the dawn of the industrial revolution in the mid-nineteenth century. On its own, blockchain is hardly revolution­ary. In conjunctio­n with the secure, remote automation of financial and machine processes, however, it can have potentiall­y farreachin­g implicatio­ns.

Ultimately, blockchain’s uses will be limited to specific, well-defined, and complex applicatio­ns that require transparen­cy and tamper-resistance more than they require speed — for example, communicat­ion with self-driving cars or drones. As for most of the coins, they are little different from railway stocks in the 1840s, which went bust when that bubble — like most bubbles — burst.

Blockchain­s are less efficient than existing databases. When someone says they are running something “on a blockchain,” they usually mean they are running one instance of a software applicatio­n on many devices.

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