Coin Market

StarkWare researchers propose smart contracts for Bitcoin with ColliderVM

Published

1 month ago

April 11, 2025

Sidechain developer StarkWare and Weizmann Institute of Science researchers claim to have created a workaround for multiple Bitcoin script limitations.

According to a recent research paper, the new design claims to allow the deployment of complex smart contracts on Bitcoin in a more capital-efficient manner. The new system may also be vastly more efficient from a computing standpoint.

ColliderVM is a protocol designed to enable stateful computation on Bitcoin, allowing multi-step processes to be securely executed over multiple transactions. Traditionally, Bitcoin script output is not accessible to other scripts, making complex calculations nearly impossible.

The researchers argue that ColliderVM could allow the use of Scalable Transparent Arguments of Knowledge (STARKs) — a type of zero-knowledge proof — on Bitcoin without requiring consensus-level changes to the network. The architecture would let Bitcoin verify complex offchain computations with minimal onchain data.

ColliderVM targets Bitcoin limitations

Each Bitcoin block can contain up to 4 million OPCodes (commands) across all transactions, and a single Bitcoin script can contain up to 1,000 stack elements (data entries). Furthermore, stateless execution means that each script executes without memory of previous state or intermediate computations from earlier transactions, making complex computations impractical.

The BitVM implementation from a 2023 paper by Robin Linus from Bitcoin research firm ZeroSync allowed for complex smart contracts on Bitcoin but required fraud proofs. Fraud proofs are cryptographic proofs that prove a particular transaction or computation was performed incorrectly, possibly triggering corrective actions.

Fraud-proof implementation typically requires operators to front capital for potential corrective actions. In BitVM, operators pay an advance to cover potentially fraudulent transactions, recovering the capital after the fraud-proof window closes.

The new system is also more efficient from a computing point of view, compared with previous implementations, but still expensive. Previous implementations used cryptographic one-time signatures (Lamport and Winternitz) that were notably computationally heavy.

ColliderVM draws from the November 2024 ColliderScript paper by researchers from StarkWare, web services firm Cloudflare and Bitcoin sidechain developer Blockstream. This system relies on a hash collision-based commitment setting a challenge to produce an input that, when run through a hash function, produces an output with pre-determined features.

This setup requires significantly fewer computing resources from honest operators than from malicious actors.

Computational resources needed by honest and malicious actors depending on collision difficulty. Source: ColliderVM paper

Hash, but no food or weed

A hash is a non-reversible mathematical function that can be run on arbitrary data, producing a fixed-length alphanumeric string. Non-reversible means that it is impossible to run the computation in reverse to obtain the original data from a hash.

This results in a sort of data ID identifying data to the bit, without containing any underlying data.

Hash function examples. Source: Wikimedia

This system — somewhat resembling Bitcoin (BTC) mining — requires significantly fewer hash operations compared to BitVM, reducing both script size and processing time. ColliderVM researchers claim to have reduced the number of those operations even further, by at least a factor of 10,000.

The researchers seemingly suggest that this implementation is nearly making a STARKs-based Bitcoin sidechain practical. The paper reads:

“We estimate that the Bitcoin script length for STARK proof verification becomes nearly practical, allowing it to be used alongside other, pairing-based proof systems common today in applications.”

STARKs are a ZK-proof system recognized for their scalability and trustless nature (no trusted setup is needed). ZK-proofs are a cryptographic system that allows users to prove a particular feature of a piece of data without revealing the underlying data.

Many early ZK-proof systems necessitated a one-time secure setup that relied on “toxic waste” data. If a party were to keep hold of the toxic waste, it would allow them to forge signatures and generate fraudulent proofs. STARKs do not rely on such a setup, making them trustless.

Traditional implementation of STARK verifiers would require scripts that exceed Bitcoin’s limits. Now, researchers behind ColliderVM argue that their more efficient system approaches make an onchain verification script for STARK-proofs “nearly practical.”

Bitcoin-based trustless sidechains?

Bitcoin is widely considered the most secure and reliable blockchain, but its critics raise issues with its feature set being significantly more limited when compared to many altcoins. Sidechains such as Blockstream’s Liquid exist, but are not trustless.

Director of research at blockchain firm Blockstream and mathematician Andrew Poelstra told Cointelegraph as far back as 2020 that ZK-proof-based systems are “one of the most exciting areas of development” in the cryptography space. Cypherpunk, a developer cited in the Bitcoin white paper and Blockstream founder, explained in a 2014 paper that more work was needed to implement trustless ZK-proof-based sidechains on Bitcoin.

Still, even 10 years later, a system based on ColliderVM would be trust-minimized rather than trustless. This is because users would still need to trust that at least a minimal subset of network participants will act honestly to ensure the correct functioning of the system.

The study’s lead authors include Eli Ben-Sasson, co-founder of StarkWare, along with researchers Lior Goldberg and Ben Fisch. Ben-Sasson is one of the original developers of STARKs and has long advocated for the use of zero-knowledge proofs to improve blockchain scalability.

In a recent interview with Cointelegraph, StarkWare co-founder Ben-Sasson noted that a real Bitcoin layer-2 solution would need to have “the security of Bitcoin itself.” Instead, current solutions rely on trust in signers or fraud-proof-based economic incentives. Still, he recognized the Lightning Network:

“We should also acknowledge there’s, of course, today, lightning networks, which have the security of Bitcoin.“

Magazine: ‘Bitcoin layer 2s’ aren’t really L2s at all: Here’s why that matters

Coin Market

India’s Supreme Court urges government to regulate cryptocurrency

Published

27 minutes ago

May 20, 2025

India’s Supreme Court has questioned the government’s lack of regulatory clarity on cryptocurrencies despite imposing taxes on digital assets like Bitcoin.

According to Indian legal news outlet LawChakra, the country’s Supreme Court expressed concern over the growing use of Bitcoin (BTC) and other cryptocurrencies while remaining largely unregulated.

“This is a whole parallel economy running with such coins and is a danger to the economy of the country,” Justice Surya Kant reportedly said during a recent hearing related to an ongoing investigation into a Bitcoin transaction.

Kant further highlighted that while the government has implemented crypto taxation, it has failed to regulate the space.

“If you can tax it at 30%, also please regulate it as you have recognised it by taxing it,” the judge said.

Government says review may follow

The Additional Solicitor General of India — a senior legal officer representing the government of India — reportedly answered the request by saying that the government “will take instructions, my lord,” indicating that the government may consider reviewing the country’s current cryptocurrency regulation.

The report follows a May 5 hearing by the Supreme Court of India during which Kant and lawyer Mahesh Jethmalani shared their views on cryptocurrency. Jethmalani explained that Bitcoin is already seeing widespread usage worldwide, noting that “in Europe, you can walk into a car showroom and buy a car using just one Bitcoin.”

While this scenario is not as common as this statement may suggest, buying a car with Bitcoin is possible at specialized sellers. The lawyer also showed that he misunderstood the pseudonymous nature of Bitcoin’s creator, Satoshi Nakamoto, claiming that he was from Japan:

“It was created by someone from Japan who used a fake name.”

Concerns over misuse

Kant also expressed concern over the misuse of cryptocurrencies during the hearing. He said that “there is some system of rules that applies to this.”

Kant also said that “some Bitcoins are genuine, but some might not be.” However, it’s unclear whether he meant to suggest that counterfeit Bitcoin are in circulation (there are none) or that illegal activities taint some.

The latter appears likely since the statement was followed by the judge saying that “it has also become a possible way to do illegal business.”

India’s government has not yet introduced comprehensive legislation to govern cryptocurrencies, though it taxes gains and requires firms to report certain activities to financial regulators. The lack of regulation has drawn criticism from both the industry and policymakers amid the asset class’s continued growth.

Magazine: India mulls new crypto ban to support CBDC, Lazarus Group strikes again: Asia Express

Coin Market

Bitcoin privacy tool Payjoin receives $100K grant from Maelstrom

Published

1 hour ago

May 20, 2025

Bitcoin developer Ben Allen has received a $100,000 grant from investment firm Maelstrom to support the development of Payjoin, a privacy-focused tool aimed at improving Bitcoin’s scalability and privacy.

According to a May 20 announcement shared with Cointelegraph, Maelstrom will finance Allen’s work on his Payjoin devkit alongside Dan Gould. The system allows Bitcoin (BTC) senders and receivers to use batched transactions, with positive implications for scalability and privacy.

Payjoin Developer Kit’s website. Source: Payjoin Dev Kit

Payjoin was first proposed by Nicolas Dorier in 2019 in Bitcoin improvement proposal (BIP) 78. The core principle behind the system is that both senders and receivers may contribute inputs to a transaction.

“Namely that privacy is enhanced and improved consolidation of transaction outputs is achieved, benefiting scalability,“ the Maelstrom announcement states.

A Maelstrom representative told Cointelegraph that grantees are paid monthly for a total of $100,000 per year in Bitcoin and Allen’s grant will last one year. There are no concrete milestones and the grant is managed on a hands-off approach:

“We believe grantees may work better with freedom to work on what they wish, rather than being tightly controlled by those who provide the funding.“

Payjoin: Soon in wallets near you?

Allen will be working on improving Payjoin implementations, with the clear objective of making it possible for the feature to be added to more wallets. He explained that the funding will enable him to work on the project full time.

The announcement points out that the system presents challenges, with the receiver needing to be online and the payment communication flow being more complex than normal non-interactive Bitcoin transactions. Maelstrom’s chief investment officer and BitMEX crypto exchange co-founder and former CEO Arthur Hayes said that “improving financial privacy in Bitcoin is extremely important.” He added:

“The great thing about Payjoin is that if only a small amount of adoption is achieved, it breaks a key assumption used by financial surveillance companies. The assumption they have is that if a Bitcoin transaction has multiple inputs, all the inputs must all belong to the same entity.“

A Maelstrom representative explained to Cointelegraph that the firm “is keen to support more grantees in the privacy area.” The company is actively seeking candidates with strong track records in Bitcoin privacy projects.

Enjoy the benefits whether you use it or not

Hayes noted that “Payjoin adoption improves the privacy of even the people who don’t use it.” Allen said he believes privacy is important for Bitcoin users to enjoy a better experience and control their financial data when using it daily.

Allen told Cointelegraph he is “building out benchmarks to help downstream developers implement Payjoin in individual wallet software as well as expanding test coverage to ensure consistent and reproducible code.” He explained that encouraging its adoption “is the biggest step we can take for simplifying the experience and encouraging Payjoin adoption by moving the complexities mostly away from the user.”

The Maelstrom representative told Cointelegraph that “a key metric for Payjoin success would be adoption by popular open source Bitcoin wallets.” “In particular if the BitcoinCore wallet ever adopts it, that would be a huge signal of success,” they added.

Magazine: Big Questions: What did Satoshi Nakamoto think about ZK-proofs?

Coin Market

Binance seeks to dismiss $1.76B FTX lawsuit, blames SBF for collapse

Published

1 hour ago

May 20, 2025

Binance has filed a motion to dismiss a $1.76 billion lawsuit brought by the FTX estate, accusing the defunct crypto exchange of trying to deflect blame for its own failure.

Filed on May 16 in the Delaware Bankruptcy Court, Binance’s legal team called the suit “legally deficient,” stating that FTX’s collapse was not triggered by market manipulation or hostile action but by internal misconduct.

“Plaintiffs are pretending that FTX did not collapse as the result of one of the most massive corporate frauds in history,” the filing said, pointing to Sam “SBF” Bankman-Fried’s conviction on seven counts of fraud and conspiracy.

FTX’s estate alleges that Binance received billions in crypto during a 2021 buyback deal, funded improperly with customer assets.

Binance rejects this claim, stating that “FTX remained a going concern for 16 months” after the share repurchase and that there was “no plausible claim” the exchange was insolvent at the time.

Binance filing to dismiss FTX’s lawsuit against the exchange. Source: Law360news

Zhao’s tweet and FTT crash

The lawsuit also accuses former Binance CEO Changpeng Zhao of triggering a collapse through a tweet on Nov. 6, 2022 announcing the liquidation of FTT tokens.

In response, Binance argued that Zhao’s tweet was based on publicly known concerns. “Binance’s decision to liquidate its remaining FTT was, in fact, ‘due to recent revelations ’— in particular, the Nov. 2, 2022, CoinDesk article” that exposed Alameda Research’s balance sheet.

The company further defended Zhao’s comment that Binance would aim to minimize market impact. “The Complaint contains no such facts” to prove Binance had no intention of following through.

CZ announced plans to liquidate FTT holdings in 2022. Source: CZ

In challenging the court’s jurisdiction, Binance said none of the foreign entities named “are incorporated in or maintain their principal place of business in the United States,” and thus fall outside the court’s reach.

The filing also criticizes the plaintiff’s narrative as “a grab bag of state law claims” based on “pure conjecture — much of it sourced from a convicted fraudster’s hindsight speculation.”

Binance has asked the court to dismiss all claims with prejudice. The FTX estate has not yet filed its response.

FTX to disburse $5 billion in second round of creditor repayments

FTX is set to begin its second round of repayments to creditors more than two years after filing for bankruptcy.

In a May 15 notice, the FTX Recovery Trust announced that over $5 billion will be distributed starting May 30 through BitGo and Kraken, targeting parties in the second eligible group under the exchange’s reorganization plan.

According to the plan, five creditor groups categorized as “convenience classes” are expected to receive between 54% and 120% of their claims. In total, FTX may repay up to $16 billion, depending on the final number of valid claims.

Magazine: Father-son team lists Africa’s XRP Healthcare on Canadian stock exchange