Quantum computing has long been seen as a threat to cryptocurrencies, a technology that could one day crack the cryptography securing Bitcoin and other blockchains. In 2026, this fear will come to featherlight again as major technology companies accelerate quantum research and investment.

Although this technology is not yet ready for widespread apply, the pace of investment and experimentation has increased. In February, Microsoft exposed Majorana 1 chip, which the company called “the world’s first quantum chip powered by a new topological core architecture,” reigniting the debate over how quickly quantum hardware can move from research to real-world systems.

However, despite the growing attention, most experts say the risks to cryptocurrencies remain theoretical, not immediate. They argue that the real problem is not the sudden collapse of cryptography next year, but what attackers are doing today to prepare for a post-quantum future.

Clark Alexander, co-founder and head of AI at Argentum AI, told Cointelegraph that he expects quantum computing to find “extremely limited commercial application” in 2026.

Nic Puckrin, cryptocurrency analyst and co-founder of Coin Bureau, was more blunt. “The whole ‘quantum threat to Bitcoin’ narrative is 90% marketing and 10% immediate threat…We are almost certainly at least a decade away from computers that can actually break existing cryptography,” he said.

Why cryptocurrencies are at risk

Bitcoin (BTC) and most major blockchain networks rely on public key cryptography to secure wallets and authorize transactions. Private keys sign transactions, public keys verify them, and hash functions secure the ledger. If a future quantum machine is able to generate private keys from public keys, funds could theoretically be stolen on a vast scale.

Related: Willy Woo Says Bitcoin OGs Will Buy Satoshi’s Stash If Quantum Hacking Happens

The case even reached regulatory authorities in the US. In September, the U.S. Securities and Exchange Commission (SEC) Cryptocurrency Task Force received a proposal warning that quantum computing could ultimately break the encryption that protects Bitcoin and other digital assets.

On a technical level, the consensus among cryptographers is that signatures are the weakest link. “Any cryptographic system whose security relies on a mathematical problem that Shor’s algorithm can successfully solve (the difficulty of factoring large semi-prime numbers),” said Sofiia Kireieva, blockchain research and development expert and subject matter expert at Boosty Labs.

Related: Aptos introduces post-quantum signatures before they are urgently needed

She added that if an adversary with quantum capabilities attacks Bitcoin or a similar blockchain, the elliptic curve digital signature algorithm (ECDSA) used for private-public keys will be the “weakest link.” In contrast, SHA-256 hash functions are much less vulnerable to attacks. According to Kireieva, Grover’s algorithm could at best provide a quadratic speedup that could be mitigated by using larger hashes.

Ahmad Shadid, founder of the Swiss foundation O Foundation, also said the main loophole was signatures. “The cryptographic component that would be most vulnerable to attacks is the ECDSA digital signature algorithm, and in particular the security of the public/private key pairs used to sign transactions, and especially when addressing address reuse (which significantly increases vulnerability),” he said.

Related: Why Vitalik believes quantum computing could crack Ethereum’s cryptography sooner than expected

What experts expect in 2026

Despite growing concerns, significant technical barriers make crypto collapse by 2026 very unlikely.

Kireieva noticed a physical barrier standing in front of the quantum equipment. “Current quantum devices only have hundreds or thousands of noisy qubits, well below what is needed to run deep algorithms like Shor… This means that a realistic cryptanalytic attack would require millions of physical qubits, a very low gate error rate, and the ability to perform millions of sequential operations without loss of consistency,” she said.

Kireieva added that it would also require breakthroughs in materials science, quantum control, signal manufacturing and isolation. “The bottleneck isn’t just an engineering issue — it’s the fundamental physics of the universe,” she said.

Alexander went even further. He said that not only will quantum computers not break Bitcoin’s encryption until 2026, but with current approaches they may never do so. He said the real danger lies elsewhere, arguing that advances in classical computer processing pose greater risks to encryption than quantum systems, and that both quantum and conventional machines would require fundamentally fresh algorithms before public key cryptography could realistically be compromised.

Related: Adam Back: Bitcoin has no quantum risk for the next 20-40 years

The “collect now, decrypt later” problem.

Meanwhile, the real threat in 2026 is not that Bitcoin breaks; the point is that attackers are already collecting data.

“A quantum threat emerging in 2026 is highly unlikely,” said Sean Ren, co-founder of Sahara AI, “but threat actors are already collecting as much encrypted data as possible… so that when the technology is ready, all archived data will be readable.”

Leo Fan, co-founder of Cysic, shares this view, saying that the typical attack scenario is “collect now, decrypt later,” in which adversaries are already collecting sensitive encrypted data in order to unlock it when quantum breakthroughs arrive.

Shadid explained that this means someone could download terabytes of this publicly available onchain data simply to collect public keys, which can then be used in a quantum computer to decode the private keys.

Related: What will happen to Satoshi’s 1 million bitcoins if quantum computers are launched?

Millions of Bitcoins remain exposed: how is the cryptocurrency preparing?

Kireieva estimated that 25–30% of all BTC (around 4 million coins) are held at sensitive addresses, that is, addresses whose public keys have already been exposed on-chain, making them more susceptible to private key recovery by a sufficiently powerful quantum computer.

She advised users to minimize risk by avoiding address reuse, ensuring public keys remain hidden until funds are spent, and be prepared to migrate to quantum-resistant wallets and address formats as soon as they become available.

The crypto community has also taken practical steps. In July, cryptography experts outlined a plan to replace Bitcoin’s current signature systems with quantum-resistant alternatives, noting that about a quarter of Bitcoin’s funds are already exposed as a result of public keys being exposed on-chain.

In November, Qastle announced plans to bring quantum-grade security to sizzling wallets by improving the cryptography behind the scenes. Instead of relying on predictable software-based randomness, it uses quantum-generated randomness and post-quantum encryption to protect keys, transactions and communications, all without additional hardware or intricate configuration.

Related: IBM says there has been a huge step towards quantum computers with fresh chips

There is no quantum doomsday for the cryptocurrency industry in 2026. However, the discussion about risk is shifting from “if” to “when.”

“The probability that a major quantum attack… will occur by 2026 is low to moderate,” Fan said. “However, the likelihood of quantum technology becoming the most important risk factor for cryptographic security awareness in 2026… is high,” he added.

Magazine: Bitcoin vs. the Quantum Computer Threat – Timeline and Solutions (2025-2035)