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Bitcoin: how many exist, lost and its quantum computing future

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Let’s start by setting up a context of just how much it costs to verify one Bitcoin transaction. A report on Motherboard recently calculated that the cost to verify 1 Bitcoin transaction is as much electricity as the daily consumption of 1.6 American Households. Bitcoin network may consume up to 14 Gigawatts of electricity (equivalent to electricity consumption of Denmark) by 2020 with a low estimate of 0.5GW.

There is much written about theft of Bitcoin, as people are exposed to cyber criminals, but there are also instances where people are losing their coins. In case of loss, it’s almost always impossible to recover lost Bitcoins. They then remain in the blockchain, like any other Bitcoin, but are inaccessible because it’s impossible to find private keys that would allow them to be spent again.

Bitcoin can be lost or destroyed through the following actions:

Sometimes, not only individuals but also experienced companies make big mistakes and loose their Bitcoins. For example, Bitomat lost private keys to 17,000 of their customers’ Bitcoins. Parity lost $300m of cryptocurrency  due to several bugs. And most recently, more than $500 million worth of digital coins were stolen from Coincheck.

Lot Bitcoin losses also come from Bitcoin’s earliest days, when mining rewards were 50 Bitcoins a block, and Bitcoin was trading at less than 1 cent. At that time, many  didn’t care if they lost their (private) keys or just forgot about them; this guys threw away his hard drive containing 7500 Bitcoins.

Let’s briefly analyse Bitcoin’s creation and increase of supply. The theoretical total number of Bitcoins is 21 million. Hence, Bitcoin has a controlled supply. Bitcoin protocol is designed in such a way that new Bitcoins are created at a decreasing and predictable rate. Each year, number of new Bitcoins created is automatically halved until Bitcoin issuance halts completely with a total of 21 million Bitcoins in existence.

While the number of Bitcoins in existence will never exceed 21 million, the money supply of Bitcoin can exceed 21 million due to fractional-reserve banking.

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As of June 23, 2017, Bitcoin has reached a total circulation amount of 16.4 million Bitcoins, which is about 81,25% of the total amount of 21 million Bitcoins.

2017 research by Chainanalysis showed that between 2.78 million and 3.79 million Bitcoins are already lost or 17% – 23% of what’s been mined to date.

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How much Bitcoin exactly has been lost? It’s a pretty tough question considering there is no definitive metric for finding the answer. A good estimate is around 25% of all Bitcoin, according to this analysis (this research concludes 30% of all coins had been lost, equating to 25% of all coins when adjusted for the current amount of coins in circulation, which can be done as bulk of lost Bitcoins originate from very early and as Bitcoin’s value has been going up, people lose their coins at a slower rate).

With advent of quantum computers, future of Bitcoin might be perilous. One researcher suggested that quantum computers can calculate the private key from the public one in a minute or two. By learning all the private keys, someone would have access to all available bitcoin. However, a more extensive research shows that in short term, impact of quantum computers will appear to be rather small for mining, security and forking aspects of Bitcoin.

It’s possible that an arms race between quantum hackers and quantum Bitcoin creators will take place. There is an initiative that already tested a feasibility of quantum-safe blockchain platform utilizing quantum key distribution across an urban fiber network.

The below image shows encryption algorithms vulnerable and secure for quantum computing.

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And while work is still ongoing, three quantum-secure methods have been proposed as alternative encryption methodologies for the quantum computing age: lattice-based cryptography, code-based cryptography, multivariate cryptography. IOTA already  deploys Winternitz One-Time Signature (OTS) scheme using Lamport signatures, claiming to be resistant to quantum computer algorithms if they have large hash functions.

The no-cloning theorem will make it impossible to copy and distribute a decentralized ledger of qubits (quantum units of information). As qubits can’t be copied or non-destructively read, they will act more like real coins (no issue of double-spending). Quantum Bitcoin miners might support the network by doing operations which amount to quantum error correction (which might replace current Proof-of-Work or Proof-of-Stake systems) as the use of quantum entanglement will enable all network participants to simultaneously agree on a measurement result without a proof of work system.

And while we are waiting for quantum-era Satoshi to rise, check out this THEORETICAL account of how quantum computers may potentially create Bitcoin, which also contains primers on quantum computers and Bitcoin mining.

P.S. Satoshi is estimated to be in the possession of over one million coins

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Bitcoin, ICOs, Mississippi Bubble and crypto future

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Bitcoin bubble

Bitcoin has risen 10x in value so far in 2017, the largest gain of all asset classes, prompting sceptics to declare it a classic speculative bubble that could burst, like the dotcom boom and the US sub-prime housing crash that triggered the global financial crisis. Stocks in the dotcom crash were worth $2.9tn before collapsing in 2000, whereas the market cap of bitcoin currently (as of 03.12.2017) stands at $185bn, which could signal there is more room for the bubble to grow.


Many a financiers and corporate stars think there is a bubble and a huge opportunity. One of the biggest bitcoin bulls on Wall Street, Mike Novogratz, thinks cryptocurrencies are in a massive bubble (but anticipates Bitcoin reaching $40,000 by end of 2018). Ironically (or not), he’s launching a $500 million fund, Galaxy Digital Assets Fund, to invest in them, signalling a growing acceptance of cryptocurrencies as legitimate investments.  John McAfee has doubled down on his confidence in bitcoin by stating his belief it will be worth $1 million by the end of 2020.


Former Fed Chairman Alan Greenspan has said that “you have to really stretch your imagination to infer what the intrinsic value of bitcoin is,” calling the cryptocurrency a “bubble.” Even financial heavyweights such as CME, the world’s leading derivatives marketplace, is planning to tap into this gold rush by introducing bitcoin derivatives, which will let hedge funds into the market before end of 2017.


The practical applications for cryptocurrencies to facilitate legal commerce appear hampered by relatively expensive transaction fees and the skyrocketing energy costs associated with mining at this juncture. On this note, Nobel Prize-winning economist Joseph Stiglitz thinks that bitcoin “ought to be outlawed” because it doesn’t serve any socially useful function and yet consumes enormous resources.

Bitcoin mania has many parallels with Mississippi Bubble

Bitcoin’s boom has gone further than famous market manias of the past like the tulip craze or the South Sea Bubble, and has lasted longer than the dancing epidemic that struck 16th-century France, or recent bubble in 2000. Like many others events such South Sea Bubble, ultimately, it was a scheme. No (real economy) trade would reasonably take place but the company’s stock kept rising on promotion and the hope of investors.


In my view, a more illustrative example, with many parallels for Bitcoin, is Mississippi Bubble, which started in 1716.  Not only was the Mississippi Bubble bigger than the South Sea Bubble, but it was more speculative and more successful. It completely wiped out the French government’s debt obligations at the expense of those who fell under the sway of John Law’s economic innovations.


Its origins track back to 1684 when Compagnie du Mississippi (Mississippi Company) was chartered. In August 1717, Scottish businessman/economist John Law acquired a controlling interest in the then-derelict Mississippi Company and renamed it the Compagnie d’Occident. The company’s initial goal was to trade and do business with the French colonies in North America, which included most of the Mississippi River drainage basin, and the French colony of Louisiana. Law was granted a 25-year monopoly by the French government on trade with the West Indies and North America. In 1719, the company acquired many French trading companies and combined these into the Compagnie Perpetuelle des Indes (CPdI). In 1720, it acquired the Banque Royale, which had been founded by John Law himself as the Banque Generale (forerunner of France’s first central bank) in 1716.


Law then created speculative interest in CPdI. Reports were skillfully spread as to gold and silver mines discovered in these lands.  Law exaggerated the wealth of Louisiana with an effective marketing scheme, which led to wild speculation on the shares of the company in 1719. Law had promised to Louis XV that he would extinguish the public debt. To keep his word he required that shares in CPdI should be paid for one-fourth in coin and three-fourths in billets d’Etat (public securities), which rapidly rose in value on account of fake demand which was created for them.  The speculation was further fed by the huge increase in the money supply (by printing more money to meet the growing demand) introduced by Law (as he was also Controller General of Finances, equivalent to Finance Minister, of France) in order to ‘stimulate’ the economy.


CPdI’s shares traded around 300 at the end of 1718, but rose rapidly in 1719, increasing to 1000 by July 1719 and broke 10,000 in November 1719, an increase of over 3,000% in less than one year. CPdI shares stayed at the 9000 level until May 1720 when they fell to around 5000. By the spring of 1720, more than 2 billion livres of banknotes had been issued, a near doubling of the money supply in less than a year. By then, Law’s system had exploded – the stock-market bubble burst, confidence in banknotes evaporated and the French currency collapsed. The company sought bankruptcy protection in 1721. It was reorganised and open for business in 1722. However, in late 1720, Law was forced into exile and died in 1729. At its height, the capitalisation of CPdI was greater than either the GDP of France or all French government debt.

Why did Law fail? He was over-ambitious and over-hasty (like this Bitcoin pioneer?). He believed that France suffered from a dearth of money and incumbent financial system (Bitcoin enthusiasts claim it will revolutionize economies and countries like India are ideal for it) and that an increase in its supply would boost economic activity (Bitcoin aims to implement a variant of Milton Friedman’s k-percent rule: proposal to fix the annual growth rate of the money supply to a fixed rate of growth). He believed that printing and distributing more money would lower interest rates, enrich traders, and offer more employment to people. His conceptual flaw was his belief that money and financial assets were freely interchangeable – and that he could set the price of stocks and bonds in terms of money.

Law’s aim was to replace gold and silver with a paper currency (just like how Bitcoiners want to democratise/replace fiat money and eliminate banks). This plan was forced upon the French public – Law decreed that all large financial transactions were to be conducted in banknotes. The holding of bullion was declared illegal – even jewelry was confiscated. He recommended setting up a national bank (Banque Generale in 1716), which could issue notes to buy up the government’s debt, and thus bring about a decline in the interest rate.

During both South Sea and Mississippi bubbles, speculation was rampant and all manner of initial stock offerings were being floated, including:

  • For settling the island of Blanco and Sal Tartagus
  • For the importation of Flanders Lace
  • For trading in hair
  • For breeding horses

Some of these made sense, but lot more were absurd.

Economic value and price fluctuations of Bitcoin

Bitcoin is similar to other currencies and commodities such as gold, oil, potatoes or even tulips in that its intrinsic value is difficult – if not impossible – to separate from its price.

A currency has three main functions: store of value; means of exchange; and unit of account. Bitcoin’s volatility, seen when it fell 20% within minutes on November 29th 2017 before rebounding, makes it both a nerve-racking store of value and a poor means of exchange. A currency is also a unit of account for debt. As an example, if you had financed your house with a Bitcoin mortgage, in 2017 your debt would have risen 10x. Your salary, paid in dollars, etc. would not have kept pace. Put another way, had Bitcoin been widely used, 2016 might have been massively deflationary.

But why has the price risen so fast? One justification for the existence of Bitcoin is that central banks, via quantitative easing (QE), are debasing fiat money and laying the path to hyperinflation. But this seems a very odd moment for that view to gain adherents. Inflation remains low and the Fed is pushing up interest rates and unwinding QE.

A more likely explanation is that as new and easier ways to trade in Bitcoin become available, more investors are willing to take the plunge. As the supply of Bitcoin is limited by design, that drives up the price.

There are governments standing behind currencies and reliable currency markets for exchange. And with commodities, investors have something to hold at the end of the transaction. Bitcoin is more speculative because it’s digital ephemera. That isn’t true for all investments. Stockholders are entitled to a share of a company’s assets, earnings and dividends, the value of which can be estimated independent of the stock’s price. The same can be said about a bond’s payments of principal and interest.

This distinction between price and value is what allowed many observers to warn that internet stocks were absurdly priced in the late 1990s, or that mortgage bonds weren’t as safe as investors assumed during the housing bubble. A similar warning about Bitcoin isn’t possible.

What about Initial Coin Offerings (ICOs)? An ICO (in almost all jurisdictions so far) is an unregulated means, bypassing traditional fund raising methods, of raising capital for a new venture. Afraid of missing out on the next big thing, people are willing to hand their money over no matter how thin the premise, very much like in case of South Sea or Mississippi Bubbles. They have close resemblance to penny stock trading, with pump-n-dump schemes, thin disclosures and hot money pouring in and out of stocks.

ICOs, while an alternative financing scheme for startups, aren’t so far sustainable for business. Despite the fact that more than 200 ICOs have raised more than $3 billion so far in 2017, only 1 in 10 tokens is use after the ICO. And a killer app for most popular public blockchain platform Ethereum, which sees increasing number of ICOs? First ecosystem (game to trade kittens) has been launched and almost crashed Ethereum network. This game alone consumes 15% of Ethereum traffic and even than it’s hard to play due to its slowness (thanks Markus for this info bite!).

So overall, Bitcoin (and other crypto currencies) exist only for the benefit of those that buy-n-hold and use them while creating an explicit economic program of counter-economics. In other words, Bitcoin is not as much about money but power.

How it all may end (or begin)

The South Sea Bubble ended when the English government enacted laws to stop the excessive offerings. Mississippi Bubble ended when French currency collapsed, French government bought back (and ultimately wrote off debt via QE) all CPdI’s shares and cast out instigators. The unregulated markets became regulated.

From legal perspective, most likely the same thing will happen to cryptocurrencies and ICOs. China temporarily banned cryptocurrency exchanges till regulations can be introduced. Singapore, Malaysia, and other governments have plans to introduce regulations by end of 2017 or early 2018. Disregard, ignorance, or flaunting of regulatory and other government-imposed rules be mortal for startups and big businesses alike.

From technology perspective, a number of factors, including hard forks, ledger and wallet hacking and its sheer limitations related to scaling, energy consumption, security might bring it down. Also many misconceptions about blockchain/Bitcoin such as claims of a blockchain being everlasting, indestructible, miners providing security, and anonymity being a universally good thing are either exaggerated, not always or patently not true at all.

From business perspective, startups and companies raising money via ICO can be subject to fraud – Goldman Sachs’ CEO claims Bitcoin is a suitable means for conducting fraud, and thus subject to money laundering, counter-terrorist and other relevant government legislation. From investors perspective, shorting seems to be the most sure-fire way of investing profitably in cryptocurrencies.

During the dot-com craze, Warren Buffett was asked why he didn’t invest in technology. He famously answered that he didn’t understand tech stocks. But what he meant was that no one understood them, and he was right. Why else would anyone buy the NASDAQ 100 Index when its P/E ratio was more than 500x – a laughably low earnings yield of 0.2% – which is where it traded at the height of the bubble in March 2000.

It’s a social or anthropological phenomenon that’s reminiscent of how different tribes and cultures view the concept of money, from whale’s teeth to abstract social debts. How many other markets have spawned conceptual art about the slaying of a “bearwhale

Still, the overall excitement around Bitcoin shows that it has tapped into a speculative urge, one that isn’t looking to be reassured by dividends, business plans, cash flows, or use cases. Highlighting a big, round number like $10,000 only speaks to our emotional reaction to big, round numbers. But it doesn’t explain away the risk of this one day falling to the biggest, roundest number of all – zero.

Survival of blockchain and Ethereum vs. alternatives

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As outlined in my previous post, blockchain faces number of fundamental – technological, cultural, and business – issues before it becomes mainstream. However, potential of blockchain, especially if it were coupled with AI, cannot be ignored. The potent combination of blockchain and AI  can revolutionise healthcare, science, government, autonomous driving, financial services, and a number of key industries.

Discussions continue about blockchain’s ability to lift people out of poverty through mobile transactions, improve accounting for tourism in second-world countries, and make governance transparent with electronic voting. But, just like the complementary – and equally hyped – technologies of AI, IoT, and big data, blockchain technology is emerging and yet unproven at scale. Additional, socio-political as well as economic roadblocks remain to blockchain’s widespread adoption and application:

1. Disparity of computer power and electricity distribution

Bitcoin transactions on blockchain require “half the energy consumption of Ireland”. This surge of electricity use is simply impossible in developing countries where the resource is scarce and expensive. Even if richer countries assist and invest in poorer ones, the UN is concerned that elite, external ownership of critical infrastructure may lead to a digital form of neo-colonialism.

2. No mainstream trust for blockchain

Bitcoin inspired the explosive attention on blockchain, but there isn’t currently much trust in the technology – as it’s relatively new, unproven and has technical problems and limitations – outside of digital currencies. With technologies still in their infancy, blockchain companies are slow to deliver on promises. This turtle pace does not satisfy investors seeking quick ROI. Perhaps the largest, challenge to blockchain adoption is the massive transformation in architectural, regulatory, and business management practices required to deploy the technology at scale. Even if such large-scale changes are pulled off, society may experience a culture shock from switching to decentralised, automated systems after a history of only centralised ones.

3. Misleading and misguided ‘investments’

Like the Internet, blockchain technology is most powerful when everyone is on the same network. The Internet grew in fits and starts, but was ultimately driven by the killer app of email. While Bitcoin and digital currencies are the “killer app” of blockchain, we’ve already seen aggressive investments in derivative cryptocurrencies peter out.

Many technologies also call themselves “blockchain” to capitalise on hype and capture investment, but are not actual blockchain implementations. But, even legitimate blockchain technologies suffer from the challenge of timing, often launching in a premature ecosystem unable to support adoption and growth.

4. Cybersecurity risks and flaws

The operational risks of cybersecurity threats to blockchain technology make early adopters hesitate to engage. Additionally, bugs in the technology are challenging to detect, yet caused outsized damage. Getting the code right is critical, but this requires time and talent.

While relatively more known Bitcoin’s PoW-based blockchain systems and Ethereum see limelight and PR, there are number of alternative blockchain protocols and approaches, which are scalable and solve many of fundamental challenges the incumbents face.

PoW and Ethereum alternatives

Disclaimer: I neither condone, engage nor promote any of the below alternatives but simply provide information as found on websites, articles and social media of relevant entities and therefore not responsible whether the information thus provided is accurate and realistic.

1. BitShares, SteemIt (based on Steem) and EOS white papers which are all based on Delegated Proof of Stake (DPOS). DPOS enables BitShares to process 180k transactions per second, which is more than 5x NASDAQ transactions/s. Steem and Bitshares process more transactions/day than the top 20 blockchains combined.

In DPOS, each 2 seconds – Bitcoin’s PoW generates a new block each 10 minutes – a new block is created, through witnesses (stakeholders can elect any number of witnesses to generate blocks – currently 21 in Steem and 25 in BitShares). DPOS is using pipelining to increase scalability. Those 20 witnesses generate their own block in a specified order, that holds for a few rounds (hence the pipelining), after the order is changed. DPOS confirms transactions with 99.9% certainty in an average of just 1.5 seconds while degrading in a graceful, detectable manner that is trivial to recover from. It is easy to increase the scalability of this schema, by introducing additional witnesses either by increasing the pipeline length or using sharding to allow to generate in a deterministic/verifiable way few blocks during the same epoch.

2. IOTA (originally designed to be financial system for IoT) is a new blockless distributed ledger which is scalable, lightweight and fee-less. It’s based on DAG, and its performance INCREASES the bigger the networks gets.

3. Ardor solves the common (to all blockchains) bloat problem, relying on an innovative parent/child chain architecture and pruning of the child chain transactions. It shares some similarities with, based on NXT blockchain technology and already running on testnet.

4. LTCP uses State Channels by stripping 90% of the transaction data from the blockchain. LTCP combined with RSK’s Lumino network or Ethereum’s Raiden network can serve 1 billion users in both retail and online payments.

5. Stellar runs off of Stellar Consensus Protocol (SCP) and is scalable, robust, got a distributed exchange and is easy to use. SCP implements “Federated Byzantine Agreement,” a new approach to achieving consensus in a real-world network that includes faulty “Byzantine” nodes with technical errors or malicious intent. To tolerate Byzantine failures, SCP is designed not to require unanimous consent from the complete set of nodes for the system to reach agreement, and to tolerate nodes that lie or send incorrect messages. In the SCP, individual nodes decide which other participants they trust for information, and partially validate transactions based on individual “quorum slices.” The systemwide quorums for valid transactions result from the individual quorum decisions by individual nodes.

6. A thin client is a program which connects to the Bitcoin network but which doesn’t fully validate transactions or blocks, i.e it’s a client to the full nodes on the network. Most thin clients use the Simplified Payment Verification (SPV) method to verify that confirmed transactions are part of a block. To do this, they connect to a full node on the blockchain network and send it a filter (Bloom filter) that will match any transactions affecting the client’s wallet. When a new block is created, the client requests a special lightweight version of that block: Merkle block, which includes a block header, a relatively small number of hashes, a list of one-bit flags, and a transaction count. Using this information—often less than 1 KB of data—the client can build a partial Merkle tree to the block header. If the hash of the root node of the partial Merkle tree equals the hash of Merkle root in the block header, the SPV client has cryptographic proof that the transaction was included in that block. If that block then gets 6 confirmations at the current network difficulty, then the client has extremely strong proof that the transaction was valid and is accepted by the entire network.

The only major downside of the SPV method is that full nodes can simply not tell the thin clients about transactions, making it look like the client hasn’t received bitcoins or that a transaction the client broadcast earlier hasn’t confirmed.

7. Mimir proposes a network of Proof of Authority micro-channels for using in generating a trustless, auditable, and secure bridge between Ethereum and the Internet. This system aims to establish Proof of Authority for individual validators via a Proof-of-Stake contract registry located on Ethereum itself . This Proof-of-Stake contract takes stake in the form of Mimir B2i Tokens. These tokens serve as collateral that may be repossessed in the event of malicious actions. In exchange for serving requests against the Ethereum blockchain, validators get paid in Ether.

8. Ripple’s XRP ledger already handles 1,500 transactions/second on-chain, which keeps on being improved (was 1,000 transactions/sec at the beginning of 2017).

9. QTUM, a hybrid blockchain platform whose technology combines a fork of bitcoin core, an Account Abstraction Layer allowing for multiple Virtual Machines including the Ethereum Virtual Machine (EVM) and Proof-of-Stake consensus aimed at tackling industry use cases.

10. Blocko, which has enterprise and consumer grade layers and has already successfully piloted/launched products (dApps) with/for Korea Exchange, LotteCard and Huyndai.

11. Algorand uses “cryptographic sortition” to select players to create and verify blocks. It scales on demand and is more secure and faster than traditional PoW and PoS systems. While most PoS systems rely on some type of randomness, algorand is different in that you self-select by running the lottery on your own computer (not on cloud or public chain). The lottery is based on information in the previous block, while the selection is automatic (involving no message exchange) and completely random. Thanks David Deputy for pointing out this platform!!!

12. NEO, also called “Ethereum of China,”  is a non-profit community-based blockchain project that utilizes blockchain technology and digital identity to digitize assets, to automate the management of digital assets using smart contracts, and to realize a “smart economy” with a distributed network.

Bitcoin and blockchain demystified: basics and challenges

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Bitcoin, blockchain, Ethereum, gas, …

A new breed of snake oil purveyors are peddling “blockchain” as the magic sauce that will power all the world’s financial transactions and unlock the great decentralised database in the sky. But what exactly are bitcoin and blockchain?

Bitcoin is a system for electronic transactions that don’t rely on a centralised or trusted third-party (bank or financial institution). Its creation was motivated by the fact that digital currency made of digital signatures, while providing strong ownership control, was viable but incomplete solution unable to prevent double-spending. Bitcoin’s proposed solution was a peer-to-peer network using proof-of-work (in order to deter network attacks) to record a public history of transactions that is computationally impractical for an attacker to change if honest nodes control a majority of CPU power. The network is unstructured, and its nodes work with little coordination and don’t need to be identified. Truth (i.e. consensus on longest chain) is achieved by CPU voting, i.e network CPUs express their acceptance of valid blocks (of transactions) by working on extending them and rejecting invalid blocks by refusing to work on them.

Satoshi Nakamoto’s seminal paper “Bitcoin: A Peer-To-Peer Electronic Cash System” has references to a “proof-of-work chain”,“coin as a chain,” “chain of ownership”, but no “blockchain” or “block chain” ever make an appearance in it.

Blockchain (which powers Bitcoin, Ethereum and other such systems) is a way for one Internet user to transfer a unique piece of digital asset (Bitcoins, Ether or other crypto assets) to another Internet user, such that the transfer is guaranteed to be safe and secure, everyone knows the transfer has taken place, and nobody can challenge the legitimacy of the transfer. Blockchains are essentially distributed ledgers and have three main characteristics: a) decentralisation, b) immutability and c) availability of some sort of digital assets/token in the network.

While decentralisation consensus mechanisms offer critical benefits, such as fault tolerance, a guarantee of security (by design), political neutrality, they come at the cost of scalability. The number of transactions the blockchain can process can never exceed that of a single node that is participating in the network. In fact, blockchain actually gets weaker (only for transacting) as more nodes are added to its network because of the inter-node latency that logarithmically increases with every additional node.

All public blockchain consensus protocols make the tradeoff between low transaction throughput and high-degree of centralisation. As the size of the blockchain grows, the requirements for storage, bandwidth, and computing power required to fully participating in the network increases. At some point, it becomes unwieldy enough that it’s only feasible for a few nodes to process a block — that might lead to the risk of centralisation.

Currently, the blockchain (and with it, Bitcoin, Ethereum and others) challenges are:

  1. Since every node is not allowed to validate every transaction, we need nodes to have a statistical and economic means to ensure that other blocks (which they are not personally validating) are secure.
  2. Scalability is one of the main challenges. Bitcoin, despite having a theoretical limit of 4,000 transactions per second (TPS) currently has a hard cap of about 7 transactions per second for small transactions and 3 per second for more complex transactions. An Ethereum node’s maximum theoretical transaction processing capacity is over 1,000 TPS but processes between 5-15 TPS. Unfortunately, this is not the actual throughput due to Ethereum’s “gas limit, which is currently around 6.7 million gas on average for each block. Gas is the computation cost within Ethereum, which users pay in order to issue transactions or perform other actions. A higher gas limit means that more actions could be performed per-block. In order to scale, the blockchain protocols must figure out a mechanism to limit the number of participating nodes needed to validate each transaction, without losing the network’s trust that each transaction is valid.
  3. There must be a way to guarantee data availability, i.e. even if a block looks valid from the perspective of a node not directly validating that block, making the data for that block unavailable leads to a situation where no other validator in the network can validate transactions or produce new blocks, and we end up stuck in the current state (reasons a node is offline include malicious attack and power loss).
  4. Transactions need to be processed by different nodes in parallel in order to achieve scalability (one solution is similar to database sharding, which is distribution and parallel processing of data). However, blockchain’s transitioning state has several non-parallelizable (serial) parts, so we’re faced with some restrictions on how we can transition state on the blockchain while balancing both parallelizability and utility.
  5. End-users and organisations (such as banks) have hard time or don’t want to use blockchain (despite many having used or using distributed ledgers). To do a simple Bitcoin transaction requires a prior (quite a few exceptions) KYC check just to sign up on one of many crypto trading or exchange platforms.  “The Rare Pepe Game is built on a blockchain with virtual goods and characters and more,” explains Fred Wilson of USV. “And it shows how clunky this stuff is for the average person to use.”
  6. There is lot of hype, around blockchain which sets wrong expectations, misleads investments and causes lots of mistakes. Bloomberg reports that Nasdaq is seeking to show progress using the much-hyped blockchain. The Washington Post lists Bitcoin and the blockchain as one of six inventions of magnitude we haven’t seen since the printing press.  Bank of America is allegedly trying to load up on “blockchain” patents. Also, due to its volatility, uncertain status (can it be considered a legal tender such as normal fiat money or is it security, etc?),  there is much instability of holding crypto assets.
  7. Contrary to common belief, disintermediating financial institutions, so the reasoning goes, multiple parties can conduct transactions seamlessly, without paying a commission. However, according to one research, cost savings might be dubious as moving cash equity markets to a blockchain infrastructure would drive a significant increase of the overall transaction cost. Trading on a blockchain system would also be slower (at least in foreseeable future) than traders would tolerate, and mistakes might be irreversible, potentially bringing huge losses.
  8. To drive massive adoption which will induce further technological advancement, a killer app on blockchain or Ethereum would be a must. Despite much invested resources and efforts globally, So far there doesn’t seem to be one, but there arguably is potential in few areas such as digital gold, payments and tokenization.
  9. Blockchain’s immutability might pose a problem for specific types of data. The EU ‘right to be forgotten requires the complete removal of information, which might be impossible on blockchain. There are other privacy-related concerns that people might want to remove or forgotten such as previous insolvency, negative rankings, and other personal details that need to change.

To conclude, I think Ethereum is furthers along compared to PoW-based public blockchains. Ethereum is still orders of magnitude off (250x off being able to run a 10m user app and 25,000x off being able to run Facebook on chain) from being able to support applications with millions of users. If current efforts are well executed, Ethereum could be ready for a 1–10m user app by the end of 2018.

However, there are less-known alternative models that are much more scalable. Once scalability issues are solved, everything will become tokenized and connected by blockchain.