From privacy coins to shiny iris-scanning orbs, zero-knowledge proofs have become synonymous with crypto, scalability and privacy.
In 2022, investors gave over $700 million in funding to companies pushing the envelope with zero-knowledge proofs. This year, ZK-proofs has arguably become one of the biggest blockchain trends, with several major Ethereum scaling protocols hitting mainnet.
ZK-proofs are a cryptographic protocol that allows one party to prove the truth of a statement to another party without sharing any of the statement’s contents.
An often-cited example is proving to a bartender that you’re old enough to drink without showing your ID or even telling them your birthdate.
In August 2010, the user “Red” on the online forum Bitcointalk asked whether there could be a way to improve the privacy of Bitcoin transactions.
“One of the things that bugs me about bitcoin is that the entire history of transactions is completely public,” the forum-goer said. Another member piped in, suggesting that zero-knowledge proofs could be the solution.
“This is a very interesting topic,” replied Nakamoto.
“If a solution was found, a much better, easier, more convenient implementation of Bitcoin would be possible.”
However, Nakamoto wasn’t convinced the tech could get around the “double-spending” problem — a fundamental flaw that exists in all digital cash protocols where a bad actor could spend the same digital tokens more than once.
“It’s the need to check for the absence of double-spends that requires global knowledge of all transactions,” said Nakamoto.
“It’s hard to think of how to apply zero-knowledge-proofs in this case. We’re trying to prove the absence of something, which seems to require knowing about all and checking that the something isn’t included,” he argued.
Years later, someone cracks the code
Little did Nakamoto know that the cypherpunks would eventually find a way to solve the problem.
Privacy-focused cryptocurrency Zcash was launched in October 2016 by Electric Coin — a firm made up of computer scientists from the formative years of Bitcoin. Zcash was built by modifying Bitcoin’s original source code.
It was also the first time zero-knowledge proofs were used in a real peer-to-peer cryptocurrency, allowing users to hide or shield the crypto wallet address sending or receiving funds.
The founding scientist of Zcash, Eli Ben-Sasson, would then go on to found StarkWare, a company known today for using zero-knowledge proofs to scale Ethereum through rollups.
Ben-Sasson tells Magazine that the early enthusiasm from Bitcoin core developers for ZK-proofs played a “pivotal role” in his eventual co-founding of StarkWare.
“The Bitcoin 2013 conference in San Jose marked my Eureka moment.”
“Mike Hearn, a then-Bitcoin developer and one of the earliest Bitcoin adopters, went as far as to declare my talk on ZK-proofs as the most crucial of the event due to its potential impact on the future of blockchain.”
“It was there that I realized the transformative potential of the Validity Proofs I was developing,” says Ben-Sasson.
Fast forward to today, Bitcoin itself now stands ready to enter the world of ZK-proofs.
ZeroSync, a nonprofit founded by three computer scientists (and sponsored by StarkWare), is developing the world’s first ZK light client for Bitcoin.
“Long-term, we hope to bring mass scalability to Bitcoin using STARK Proofs,” said Robin Linus, co-founder of ZeroSync.
Linus said that ZeroSync has designed and is currently implementing a layer-2 protocol that could allow Bitcoin to process more than 100 transactions per second while bringing privacy properties to Bitcoin.
“This could be a major feat in bringing Bitcoin toward the scalability it needs.”
So what would Nakamoto think?
“It’s evident from Satoshi’s past remarks that he strongly favored the use of ZK-proofs for privacy,” says Ben-Sasson.
Nakamoto was a stickler for anonymity. His public interactions on Bitcointalk and his emails were all reportedly done using the IP-masking browser, Tor. It’s the main reason his public IP address could never be traced back to him.
The Bitcoin creator even dedicated a section to privacy in the Bitcoin white paper, suggesting users keep their public keys anonymous so that, even though the public can see transactions occurring, they don’t know who is involved, like a stock exchange.
“It’s clear that Satoshi would have been intrigued by the privacy innovations my peers and I contributed to at Zcash,” says Ben-Sasson.
Unfortunately, Nakamoto never approached the subject again before he vanished from the public eye on Dec. 12, 2010 — the date of his last post on Bitcointalk.
“While they have recently found their way into Bitcoin through ZeroSync, I believe Satoshi would have been inclined to make the necessary adjustments to integrate them further,” he says.
“After all, for Bitcoin to realize its vision as a global currency, the imperative to scale cannot be ignored, especially considering its current state of ossification.”
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Felix Ng
Felix Ng first began writing about the blockchain industry through the lens of a gambling industry journalist and editor in 2015. He has since moved into covering the blockchain space full-time. He is most interested in innovative blockchain technology aimed at solving real-world challenges.
The government has said the £3 cap would stay in place for another year, until December 2025.
But speaking on Sunday morning with Trevor Phillips, Transport Secretary Louise Haugh indicated the government was considering abolishing the cap beyond that point to explore alternative methods of funding.
She said: “We’ve stepped in with funding to protect it at £3 until 31 December next year. And in that period, we’ll look to establish more targeted approaches.
“We’ve, through evaluation of the £2 cap, found that the best approach is to target it at young people.
“So we want to look at ways in order to ensure more targeted ways, just like we do with the concessionary fare for older people, we think we can develop more targeted ways that will better encourage people onto buses.”
Pressed again on whether that meant the single £3 cap would be removed after December 2025, and that other bus reliefs could be put in place, she replied: “That’s what we’re considering at the moment as we go through this year, as we have that time whilst the £3 cap is in place – because the evaluation that we had showed, it hadn’t represented good value for money, the previous cap.”
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It comes after Ms Haigh also confirmed that HS2 would not run to Crewe.
There had been reports that Labour could instead build an “HS2-light” railway between Birmingham and Crewe.
But Ms Haigh said that while HS2 would be built from Birmingham to Euston, the government was “not resurrecting the plans for HS2”.
“HS2 Limited isn’t getting any further work beyond what’s been commissioned to Euston,” she added.
Last month the prime minster confirmed the £2 bus fare cap would rise to £3 – branded the “bus tax” by critics – saying that the previous government had not planned for the funding to continue past the end of 2024.
He said that although the cap would increase to £3, it would stay at that price until the end of 2025 “because I know how important it is”.
Manchester mayor to keep £2 cap
The cap rise has been unpopular with some in Labour, with Greater Manchester mayor Andy Burnham opting to keep the £2 cap in place for the whole of 2025, despite the maximum that can be charged across England rising to £3.
The region’s mayor said he was able to cap single fares at £2 because of steps he took to regulate the system and bring buses back into public ownership from last year.
He also confirmed plans to introduce a contactless payment system, with a daily and weekly cap on prices, as Greater Manchester moves towards a London-style system for public transport pricing.
Under devolution, local authorities and metro mayors can fund their own schemes to keep fares down, as has been the case in Greater Manchester, London and West Yorkshire.
Shelves will not be left empty this winter if farmers go on strike over tax changes, a cabinet minister has said.
Louise Haigh, the transport secretary, said the government would be setting out contingency plans to ensure food security is not compromised if farmers decide to protest.
Farmers across England and Wales have expressed anger that farms will no longer get 100% relief on inheritance tax, as laid out in Rachel Reeves’s budget last month.
Welsh campaign group Enough is Enough has called for a national strike among British farmers to stop producing food until the decision to impose inheritance tax on farms is reversed, while others also contemplate industrial action.
Asked by Trevor Phillips if she was concerned at the prospect that shelves could be empty of food this winter, Ms Haigh replied: “No, we think we put forward food security really as a priority, and we’ll work with farmers and the supply chain in order to ensure that.
“The Department for Environment, Food and Rural Affairs will be setting out plans for the winter and setting out – as business as usual – contingency plans and ensuring that food security is treated as the priority it deserves to be.”
From April 2026, farms worth more than £1m will face an inheritance tax rate of 20%, rather than the standard 40% applied to other land and property.
However, farmers – who previously did not have to pay any inheritance tax – argue the change will mean higher food prices, lower food production and having to sell off land to pay.
Tom Bradshaw, the president of the National Farmers Union, said he had “never seen the united sense of anger that there is in this industry today”.
“I don’t for one moment condone that anyone will stop supplying the supermarkets,” he said.
“We saw during the COVID crisis that those unable to get their food were often either the very most vulnerable, or those that have been working long hours in hospitals and nurses – that is something we do not want to see again.”
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Farmers ‘betrayed’ over tax change
Explaining why the tax changes were so unpopular, he said food production margins were “so low”, and “any liquid cash that’s been available has been reinvested in farm businesses” for the future.
“One of the immediate changes is that farms are going to have to start putting money into their pensions, which many haven’t previously done,” he said.
“They’re going to have to have life insurance policies in case of a sudden death. And unfortunately, that was cash that would previously have been invested in producing the country’s food for the future.”
Sir Keir has staunchly defended the measure, saying it will not affect small farms and is aimed at targeting wealthy landowners who buy up farmland to avoid paying inheritance tax.
However, the Conservatives have argued the changes amount to a “war on farmers” and have begun a campaign targeting the prime minister as a “farmer harmer”.
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‘Farmers’ livelihoods are threatened’
Speaking to Sunday Morning With Trevor Phillips, shadow home secretary Chris Philp said he was happy with farmers protesting against the budget – as long as their methods and tactics were “lawful”.
“What the Labour government has done to farmers is absolutely shocking,” he said.
“These are farmers that, you know, they’re not well off particularly, they’re often actually struggling to make ends meet because farming is not very profitable these days. And of course, we rely on farmers for our food security.
Addressing the possible protests, Mr Philp said: “I think people have a right to protest, and obviously we respect the right to protest within the law, and it’s up to parliament to set where the law sits.
“So I think providing they’re behaving lawfully, legally, then they do have a right to protest.”