Quantum Computing Risks: Preparing Blockchains for Post-Quantum Security in 2026

A quantum computer did not hack into anyone's private keys, but there was still a Bitcoin sell-off in February 2026. There were several reasons for this drop in leverage and miner forced selling; however, VanEck cited five major developments that caused the issue related to quantum computing.

The idea that institutional selling is driven by both physical market conditions and speculative cryptographic risk represents a paradigm shift in risk or investment decision making through cryptocurrency.

When the price of Bitcoin fell 19% over a week (on February 5), it was priced at $60,000; VanEck says this is the largest single deleveraging event in the history of cryptocurrency.

The open interest in futures dropped from over $61 billion down to just under $49 billion. Also, while academics considered quantum computing an interesting area for study, it has now transitioned into an area of palpable concern to portfolio-level managers where the narrative around uncertainty created real levels of concern among those managing portfolios with digital currencies.

Although there is no immediate threat associated with quantum computing as it relates to digital currency, the closing window of time available for those who wish to have a significant opportunity to prepare for a possible future threat cannot be overestimated.

Bitcoin's February Crash: Deleveraging, Not Destruction

According to research from VanEck, to understand what happened during February's drop as opposed to what the headlines were stating around the same time, you need to comprehensively analyze the data behind it using their extensive research about digital assets. Head of Digital Asset Research Matthew Sigel described the selloff as "an orderly deleveraging and not a capitulation." The single day crash of Bitcoin on 5th February was one of the fastest crashes for Bitcoins in history with a rate of change z-score of -6.05 standard deviations; however instead of crashing in a chaotic manner, both the price drop and decrease in leverage were almost perfectly correlated together. A large portion of the downside risk was already absorbed before the sell-offs (the RSI had entered oversold territory). Bitcoin rebounded from its lows to $60,000 by 6th February, then to $70,000 by 10th February - representing an outsized recovery relative to prior similar market events in the crypto world.

The structural environment is important to consider, especially as miners were forced to sell Bitcoin due to increasing financing conditions that pressured them to do so in order for them to finance their capital expenditures and balance sheets, thereby increasing the supply of Bitcoin on the spot market at the worst time. As well, there has been a record amount of funds flowing out of ETFs totaling $6.18 billion over three months - the longest period of time since the first introduction of spot Bitcoin ETFs. Sigel of VanEck has also indicated that concerns regarding governance have returned to discourse along with the long-term risk discussions regarding quantum computing, and security resulting from post-quantum computing.

Additionally, because there were existential threat narratives that didn't match the timelines being implied by the market, quantum related equities sold off along with other high-risk equities. The selloff was not driven by the technology side, but rather the macro side. Market infrastructure continued to operate as expected during the crash, institutional tokenization continued to grow, while stablecoin usage continued to accelerate as well.

The Quantum Threat: What It Actually Means for Crypto

The most significant flaw is easy to identify: The majority of large blockchains like Bitcoin have their public/private key pairs generated with elliptic curve cryptography (ECC) algorithms (most often digital signature algorithm-based ECC, or (ECDSA) with secp256k1). Theoretically speaking, if a powerful quantum computer could execute Shor's Algorithm effectively enough, private keys could be derived from public keys, which would result in being at risk for theft of funds as well as signature forgery. A large portion of the approximately $718 billion worth of Bitcoin currently held within public-key addresses is from older Pay-to-Public-Key (known as "P2PK") addresses, which means that the public keys in these accounts are publicly available for all time. According to Chainalysis, the amount of Bitcoin stored in these types of address is estimated to be approximately 10,200 BTC or less than 0.02% of total BTC supply that could cause something considered a market disruption if they were to be stolen. CoinShares then estimates that there are an overall total of about 1.6 million BTC (8% of the overall total BTC supply) that could create some sort of significant financial disruption if the key information were obtained from those account holders by a quantum computing attack.

The timeframe is important because today's quantum computers are not capable of breaking crypto (or Bitcoin) cryptography; for example, to decrypt Bitcoin requires millions to billions of stable, fault-tolerant qubits, while the maximum number of qubits in a quantum processor today (like Google's Willow) has just 105 qubits. CoinShares reports that this means quantum computers will need to be at least several hundred times more powerful than existing quantum systems. Grayscale states that although there is indeed a risk from quantum computers to Bitcoin cryptography, that risk will not have any immediate effect on current prices, making quantum computers a "red herring" when it comes to 2026 valuations. Jensen Huang from Nvidia believes we will have "very useful" quantum computers in 15 - 30 years, yet Christopher Wood from Jefferies has already taken Bitcoin's 10% weighting from his model portfolio because of quantum volatility, which illustrates how perceptions tend to drive market movements as opposed to technical data.

Why Bitcoin's Governance Problem Makes Quantum Preparation Urgent

The urgency with which Bitcoin is governed now has an advantage over quantum computing in general. The research done by a16z Crypto states that Bitcoin was made to be modified very slowly. If there were a controversial update in the Bitcoin protocol, there would be a risk of the protocol undergoing a destruction through a hard fork. In order for the community to perform an effective post-quantum migration, every holder of bitcoin must actively moves their bitcoins into new quantum-resistant addresses. The bitcoins that do go abandoned cannot be secured. There are estimates that there are hundreds of billions of dollars' worth of Bitcoins that have been quantum vulnerable may ultimately have been abandoned by investors.

Ultimately, the community must choose to either consider unmigrated coins as burned or to make them the first target of whoever can build a quantum computer capable of breaking cryptocurrencies at an effective level.

BTQ Technologies is the first to create a quantum-resistant form of Bitcoin using NIST-Approved post-quantum cryptography by replacing all susceptible ECDSA digital signatures with NIST standardized ML-DSA Digital Signatures. The viability of these post-quantum algorithms to serve as an alternative to existing ECDSAP signatures has been verified by various "Bitcoin Quantum" testnets run as a proof of concept. However, the transition from a testnet implementation to an entire network-wide deployment in a timely manner may take years, with many variables needing to be addressed along the way including community consensus, miner coordination, wallet updates, exchange support, etc. A group of Cryptography experts have developed an implementation strategy for the transition away from ECDSA signature methodology in July 2025 to replace ECDSA signatures that current have approximately 25% of all Bitcoins at risk. Time is running out!

Ethereum and Zcash: Different Approaches to Post-Quantum Security

Ethereum provides structural advantages in addressing comparable cryptographic flaws. Faster protocol modifications are made possible by its active development roadmap and more flexible governance approach. Research on zkEVM from the Ethereum Foundation has developed zero-knowledge proof systems that may use post-quantum primitives. EIP suggestions for quantum-resistant signature systems are being discussed, and Vitalik Buterin has written about privacy and quantum resistance. Cryptographic advancements that could incorporate post-quantum standards as they develop are currently part of the road to complete danksharding and EIL (Ethereum Interoperability Layer). Upgrading millions of smart contracts and DeFi protocols throughout the ecosystem is Ethereum's implementation scale difficulty.

Zcash, which has encrypted or hidden transaction information that could have been uncovered in the past, will be at greater risk from quantum computing than Bitcoin due to its shielded transactions being able to be "harvested today and decoded later" by bad actors (taking encrypted data from the blockchain today, with the intention of some future quantum machine decoding the encryption and uncovering the origin of that data). Bitcoin does not share this vulnerability because even though there is a possibility of forging a signature on the public ledger, there is only a risk if you engage in signature forgery; therefore, you do not need to worry about someone harvesting your signature. Zcash will have completed the Tachyon upgrade of Halo 2 in preparation for achieving quantum resistant privacy by 2027-2028. Since Majorana 1 was released by Microsoft in February of 2026 and discussions have begun regarding the timeline for quantum hardware, it is unlikely that there will be a quantum catastrophe in the cryptocurrencies market in 2026. However, it is unclear whether there will be any quantum catastrophes due to the gradual nature of protocol changes, so the question of when a quantum threat will manifest is secondary to the question of how quickly the protocol can be made quantum resistant. Consequently, the discussion has changed from "if" to "when".

What Investors Should Actually Worry About

Bitcoin has become increasingly attractive for investors with a more favorable risk-reward opportunity over the next 1 to 2 years, according to VanEck's Sigel. Deleveraging wiped out the excess leverage from last year's high of $60K and now there are signs of mean reversion in the price of Bitcoin, as well as many institutional buyers, including Fidelity and BlackRock, stepping in to buy hundreds of millions of dollars worth of It was reported that there was an increase in selling pressure during the previous event due to the quantum war narrative; however, all of the technology underlying crypto (including tokenization, DeFi plumbing, and stablecoins) remained intact during the crash. The real risk to Bitcoin in the next year is not a quantum computer breaking it; it is that crypto will not migrate fast enough to face this problem, which will take years of coordination to solve. There are NIST standards, there are testnets being tested, crypto works, but the social agreement and governance behind implementing it are lacking. This is especially true with Bitcoin, which has more roadblocks than the mathematics behind it.