A new report from Ark Invest, the firm led by tech investor Cathie Wood, and Bitcoin-focused Unchained, assesses the impact of quantum computing on Bitcoin's security. While acknowledging that quantum computing presents a long-term risk, the analysis concludes it is not an immediate threat.
The report suggests that current quantum systems lack the capability to compromise Bitcoin's cryptographic foundations. Significant advancements would be required, a progression expected to unfold over years or decades, not as a sudden event.
Bitcoin's security relies on elliptic curve cryptography and hash functions. Future quantum computers could potentially break these, leading to concerns about data being harvested now for later decryption. However, the report highlights that today's quantum computers operate in the "Noisy Intermediate-Scale Quantum" (NISQ) era, far from the capability needed to break Bitcoin keys.
Researchers estimate that practical quantum computing advancements will first emerge in fields like chemistry before impacting cryptography. They project that the Bitcoin developer community will have 10 to 20 years to adapt and optimize post-quantum cryptography solutions for the blockchain.
Under certain conditions, an estimated 35% of the Bitcoin supply could be exposed to quantum attacks if elliptic curve cryptography is eventually compromised. This includes Bitcoin held in vulnerable P2PK addresses and reused or Taproot addresses that could be migrated.
Bitcoin may eventually require post-quantum cryptography, necessitating a consensus upgrade. The integration of such protections involves complex changes to the network's consensus rules, requiring agreement across its decentralized community of developers, miners, and users. Discussions and development for these upgrades could span five to 10 years, a pace influenced by the perceived urgency of the threat.