What did Quantus warn about quantum computing and crypto?

Quantus warned that more than $2 trillion worth of crypto assets could eventually be at risk from quantum computers capable of breaking current cryptographic security systems. The report argues that the industry needs to begin preparing for migration to quantum-resistant security standards.

Why could quantum computers threaten Bitcoin and Ethereum?

Bitcoin and Ethereum rely on cryptographic signature schemes such as ECDSA and Ed25519 to secure wallets and transactions. A sufficiently powerful quantum computer running Shor's algorithm could theoretically break these systems and expose private keys.

What is Shor's algorithm and why is it important?

Shor's algorithm is a quantum computing method that can solve certain mathematical problems much faster than classical computers. It is widely viewed as the primary theoretical threat to modern public-key cryptography used across financial systems and blockchain networks.

Why is crypto harder to upgrade than the internet?

Traditional internet companies can update cryptography through software upgrades controlled by centralised operators. Blockchain networks require coordination among users, exchanges, wallet providers, validators, custodians and governance communities, making migration significantly more complex.

Why is Bitcoin considered the hardest blockchain to protect?

Quantus estimates that between 2.3 million and 3.7 million Bitcoin are permanently inaccessible because the private keys have been lost. These coins cannot be migrated to quantum-safe addresses, creating difficult decisions for the network if quantum threats become real.

How soon could quantum computers become a serious crypto risk?

Quantus argues that the planning horizon has shifted toward 2030 as advances in quantum hardware accelerate. However, the exact timing remains uncertain, and many researchers continue to debate when practical attacks might become possible.

What are post-quantum cryptography standards?

Post-quantum cryptography refers to encryption and signature systems designed to resist attacks from quantum computers. The US National Institute of Standards and Technology (NIST) finalised its first post-quantum standards in 2024.

Why would quantum-safe Bitcoin transactions be larger?

The report estimates that a quantum-safe Bitcoin signature using ML-DSA-87 could increase cryptographic payload sizes from about 97 bytes to more than 7,000 bytes. This roughly 70-fold increase could create pressure on block space and transaction throughput.

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Quantus warns quantum threat to crypto

Written by Isaac FrancisPublished May. 29 2026Last Updated May. 29 2026

A new report from Quantus warned that the cryptocurrency industry is not moving quickly enough to prepare for quantum computers that could eventually compromise the cryptographic systems securing more than $2 trillion in digital assets.

The report said advances in quantum hardware and cryptanalysis have shortened the expected timeline for attacks on cryptographic standards such as ECDSA and Ed25519, which underpin Bitcoin, Ethereum and many other blockchain networks.

“Crypto does not get a clean warning bell before Q-Day,”

Said Quantus chief executive Christopher Smith.

Quantus argued that blockchains face a more difficult transition than traditional internet platforms because public keys remain permanently exposed on-chain and any migration would require coordination among users, exchanges, custodians, wallet providers and network validators.

The report highlighted Bitcoin as a particularly challenging case because an estimated 2.3 million to 3.7 million BTC are permanently inaccessible, preventing those coins from being moved to quantum-resistant addresses.

Quantus also estimated that adopting post-quantum cryptography could significantly increase transaction sizes, with a quantum-safe Bitcoin signature potentially requiring around 70 times more data than current signature schemes.

The report comes as post-quantum cryptography standards finalised by the US National Institute of Standards and Technology in 2024 are increasingly being adopted by technology companies, while much of the cryptocurrency industry is still debating migration strategies and long-term implementation plans.

At the time of reporting, Bitcoin price was $73,650.53.