As cryptocurrency infrastructure and technical risks remain in the spotlight, Dan Robinson, a researcher at Paradigm, has brought a new method to the fore to help Bitcoin investors prepare for threats posed by future quantum computers. In his May 1 article, Robinson introduced a system called “Provable Address Control Timestamps” (PACTs), which aims to help long-term holders brace for quantum risks without having to reveal their identities or move their funds.
How the PACTs system works
Robinson’s approach allows users to cryptographically prove control over their private keys without making any transactions. This proof is timestamped and securely recorded using Bitcoin’s current infrastructure, allowing it to remain hidden. In the future, if necessary, users could employ zero-knowledge proofs and related technologies to demonstrate they previously owned certain assets, all without exposing sensitive information.
Robinson argues that he recommends this method because it “enables Bitcoin holders to protect themselves without having to initiate any public transaction.”
The PACTs scheme envisions that, if Bitcoin eventually transitions to a quantum-resistant system, the stored proofs would let users reassert control over their assets. However, successful implementation depends on future consensus within the community to recognize these proofs as valid.
How PACTs differs from other solutions
With quantum risks being taken seriously, the Bitcoin ecosystem has seen several proposals. Among them, BIP-361, developed by Jameson Lopp, stands out. It offers users a fixed transition period to migrate their assets to quantum-resistant addresses, after which legacy addresses become unusable.
However, BIP-361 relies on recovery mechanisms tied to the BIP-39 standard, introduced in 2013. Wallets created prior to this standard, including early Satoshi Nakamoto-associated addresses, lack recovery phrases. By contrast, PACTs operates directly with private keys regardless of wallet age, offering protection for both old and new Bitcoin addresses.
Each method presents its own strengths and trade-offs. PACTs emphasizes privacy, allowing users to secure their assets without tipping off the market or third parties. For these protections to have practical effect, though, the broader development community and network participants must eventually accept these proofs.
How soon is the quantum threat?
Currently, quantum computers are not capable of breaking Bitcoin’s cryptographic protections. Experts say reaching that capability will take years. Nevertheless, the gap is closing, and once such technology becomes viable, older Bitcoin addresses—many of which have already revealed their public keys—could become targets if their funds remain unmoved.
This raises the question: when will the risk become a genuine concern? While some investors choose to wait, others are already following discussions and considering precautionary strategies.
Although quantum computers are not yet powerful enough to compromise Bitcoin, experts highlight that the technological gap could close over time. All eyes are on which solution the Bitcoin community will ultimately adopt.
