Predictions that Bitcoin and other cryptocurrencies will fail typically elicit a broader defence 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.
Bitcoin is the first, and the biggest, “cryptocurrency” – a decentralised tradeable digital asset. Whether it is a bad investment is the big question. Bitcoin can only be used as a medium of exchange and in practice has been far more important for the dark economy than it has for most legitimate uses. The lack of any central authority makes Bitcoin remarkably resilient to censorship, corruption – or regulation. That means it has attracted a range of backers, from libertarian monetarists who enjoy the idea of a currency with no inflation and no central bank, to drug dealers who like the fact that it is hard (but not impossible) to trace a Bitcoin transaction back to a physical person.
The required storage space and computational power is substantially greater, and the latency higher, than in the case of a centralized 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 5-7 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 centralized 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.
Although we can be fairly sure that blockchain will not unseat TCP-IP, a particular blockchain component – such as Tezos or Ethereum’s smart-contract languages – could eventually set a standard for specific applications, just as Enterprise Linux and Windows did for PC operating systems. But betting on a particular “coin,” as many investors currently are, is not the same thing as betting on adoption of a larger “protocol.” Given what we know about how open-source software is used, there is little reason to think that the value to enterprises of specific blockchain applications will capitalize directly into only one or a few coins.
A third false claim concerns the “trustless” utopia that blockchain will supposedly…