Introduction to PACTs
On May 1, Dan Robinson, a general partner at Paradigm Bitcoin, unveiled a groundbreaking proposal known as Provable Address-Control Timestamps (PACTs). This innovative system is designed to assist dormant Bitcoin holders in secretly timestamping their ownership of keys prior to the emergence of quantum computing technologies, which pose a significant risk to cryptocurrency security. The implications of this proposal could be profound, especially for an estimated 1.1 million BTC linked to Satoshi Nakamoto, Bitcoin’s enigmatic creator.
The Satoshi Problem
Robinson introduces PACTs as a solution to what he describes as the ‘Satoshi Problem’, which emerges in discussions about quantum threats to Bitcoin. According to the official announcement from Paradigm, the core issue lies in the potential arrival of quantum computers that could exploit vulnerabilities within Bitcoin’s existing frameworks. If these advanced computers become operational before Bitcoin has adapted, wallets that rely on exposed public keys may face significant risks, including theft.
Furthermore, if the Bitcoin network were to hastily implement a soft fork to secure these addresses, it could force dormant holders into a public migration of their coins.
Details of the PACTs Proposal
The PACTs proposal presents an alternative route that would allow Bitcoin holders to privately timestamp their ownership evidence in 2026, without requiring any immediate additional actions until a more standardized rescue process is established. Recent reports highlight that there are approximately 1.7 million BTC stored in address types that are susceptible to quantum attacks, encompassing wallets linked to Satoshi that are valued around $75 billion.
This initiative builds upon the foundational work of BIP-361, a proposal by Jameson Lopp, the Chief Strategy Officer of Casa, which details a gradual transition away from outdated signatures, warning that any coins not migrated would ultimately be frozen. However, Robinson pointed out that various critical elements—such as multisig setups, complex scripts, and hardware wallets—would necessitate further standardization, noting the possibility that Bitcoin may not ever fully implement a quantum-resistant solution.
Industry Reactions and Concerns
The debate surrounding quantum threats to Bitcoin has gained momentum, particularly after Blockstream CEO Adam Back‘s remarks during Paris Blockchain Week in early 2026, wherein he promoted optional upgrades that bolster quantum resistance instead of mandating immediate wallet freezes. This directly contrasts the direction proposed by BIP-361, against which PACTs are aligned.
Industry leaders like David Carvalho, CEO of Naoris Protocol, have expressed urgent concerns that dormant wallets, including those owned by Satoshi, could become vulnerable to attacks as quantum technology evolves. Carvalho cautioned that a successful quantum breach of Bitcoin would severely undermine trust in the cryptocurrency.
Conclusion
In summary, Robinson’s PACTs suggest a cautious yet proactive strategy to safeguard against emerging quantum threats, potentially allowing long-dormant Bitcoin holdings to remain secure while waiting for a comprehensive solution to be finalized.
