A new Bitcoin Improvement Proposal (BIP) aims to tackle the threat posed by quantum computers by phasing out Bitcoin’s legacy signature schemes, which can be vulnerable to quantum attacks, in favor of quantum-resistant alternatives.
The proposal, titled “Post Quantum Migration and Legacy Signature Sunset,” was drafted earlier this week by a group of cryptography and blockchain experts, including American software engineer Jameson Lopp and BitcoinQS founder Christian Papathanasiou.
While quantum computers powerful enough to crack Bitcoin’s cryptography are not yet here, recent developments have narrowed the window. Some academic forecasts suggest quantum machines capable of threatening Bitcoin (BTC) could arrive as early as 2027 to 2030, per McKinsey.
Bitcoin currently relies on ECDSA and Schnorr signatures to secure transactions. Still, about a quarter of all Bitcoin’s unspent outputs have already revealed public keys onchain, making those funds particularly vulnerable to a quantum adversary.
“A successful quantum attack on Bitcoin would result in significant economic disruption and damage across the entire ecosystem,” the proposal warns. “Beyond its impact on price, the ability of miners to provide network security may be significantly impacted.”
Related: Quantum computers could bring lost Bitcoin back to life: Here’s how
Phased approach to address quantum computing risks
The proposal suggests a phased approach to address the risks posed by quantum computers. The first phase suggests stopping people from sending Bitcoin to older, less secure addresses that quantum computers could easily break.
About five years after this change, the plan will go further by making it impossible to spend any Bitcoin stored in those old, vulnerable addresses, essentially freezing those coins.
There is also a possible future step being studied, which might allow people to recover their frozen Bitcoin by proving ownership with special cryptographic methods linked to their wallet’s backup phrase, but this part depends on further research and demand.
“The longer we postpone migration, the harder it becomes to coordinate,” the authors write. They argue that a clear, time-boxed plan will create certainty, align stakeholders, and minimize the risk of catastrophic quantum theft.
Related: Google unveils new quantum computing chip: Clock ticking for crypto encryption?
Quantum computing threatens Bitcoin
In a recent opinion for Cointelegraph, David Carvalho, CEO of Naoris Protocol, said that the rise of quantum computing poses the most serious threat to Bitcoin’s security yet, potentially capable of breaking its cryptographic protections within five years or less.
He noted that recent advances, like Microsoft’s Majorana chip, have accelerated the development of powerful quantum computers, which operate differently from classical machines. These quantum systems threaten Bitcoin’s core security algorithms, especially as about 30% of BTC coins sit in addresses vulnerable to quantum attacks.
“A breach would be catastrophic for holders, whose funds would be gone forever, and the ecosystem at large,” Carvalho said. He added that the real threat isn’t quantum technology itself, but the “community’s delay in acting decisively to secure Bitcoin’s future.”
Magazine: Bitcoin vs. the quantum computer threat — Timeline and solutions (2025–2035)