Q-Day Is Imminent. Can Bitcoin Survive the Quantum Threat? - Unchained Recap

Podcast: Unchained

Published: 2026-01-18

Duration: 41 minutes

Guests: Alex Pruden

Summary

Alex Pruden, CEO of Project Eleven, discusses the looming quantum threat to Bitcoin and other blockchains. He argues that adopting post-quantum cryptography is crucial for their survival, predicting a possible Bitcoin chain split.

What Happened

Alex Pruden, CEO of Project Eleven, outlines the potential impact of quantum computing on Bitcoin and other cryptocurrencies. He explains that quantum computers, using algorithms like Shor's, can break current cryptographic systems, posing a direct threat to blockchain security. This is particularly concerning for Bitcoin, where approximately 30% of coins are under exposed public keys vulnerable to quantum attacks.

Pruden mentions Google's Willow chip, marking significant progress in quantum computing, although engineering challenges remain. The timeline for quantum threats ranges from as soon as 2-3 years to several decades, but Pruden stresses the need for immediate action to safeguard crypto assets.

Solana, a blockchain whose addresses are raw public keys, is fully vulnerable to quantum attacks, unlike Bitcoin's UTXO system, where only public keys are exposed during transactions. Ethereum, on the other hand, is already considering post-quantum cryptography as part of its future upgrades.

Project Eleven, recently funded with $20 million from investors like Castle Island Ventures and Coinbase Ventures, aims to build quantum-resilient cryptographic infrastructure. Their tool, Yellow Pages, enables users to generate post-quantum key pairs and attest ownership of Bitcoin assets, offering a potential solution to the quantum threat.

Pruden suggests that implementing post-quantum cryptography would be the most significant upgrade in blockchain history. However, Bitcoin's decentralized nature could complicate this transition, possibly leading to a chain split if consensus on how to handle the quantum threat is not reached.

There is also a contentious debate within the Bitcoin community regarding Satoshi's Bitcoins, which could be vulnerable to quantum attacks. Options include letting them be stolen, burning them, or reallocating them, each with significant implications for Bitcoin's future.

Additionally, Pruden highlights the importance of agile, future-proof infrastructure that can quickly adapt to new security challenges. He also notes the potential benefits quantum computing could bring to blockchain systems, such as quantum key distribution and randomness generation.

Key Insights

• Quantum computers, using algorithms like Shor's, can break current cryptographic systems, posing a direct threat to Bitcoin's security, with approximately 30% of coins under exposed public keys vulnerable to quantum attacks.
• Solana's blockchain is fully vulnerable to quantum attacks due to its addresses being raw public keys, unlike Bitcoin's UTXO system, where public keys are only exposed during transactions.
• Project Eleven, funded with $20 million from investors including Castle Island Ventures and Coinbase Ventures, is developing quantum-resilient cryptographic infrastructure, including a tool called Yellow Pages for generating post-quantum key pairs.
• The Bitcoin community faces a contentious debate over Satoshi's Bitcoins, which are vulnerable to quantum attacks, with options ranging from allowing them to be stolen to burning or reallocating them, each with significant implications for Bitcoin's future.