Key Highlights
Jameson Lopp said freezing 5.6 million dormant BTC would be preferable to letting future quantum attackers seize the coins.
The comments add momentum to Bitcoin’s growing debate over whether old coins in legacy addresses should be protected through a protocol change, even if that leaves some holdings permanently unspendable.
Lopp’s view aligns with a draft proposal for a phased migration to post-quantum protections that could eventually invalidate spending from legacy vulnerable outputs if owners do not move funds in time.
Bitcoin security engineer Jameson Lopp said he would rather see millions of long-dormant bitcoin frozen than fall into the hands of attackers if quantum computing ever breaks the network’s legacy cryptography, adding fresh weight to one of the ecosystem’s most divisive security debates.
The debate centers on old coins held in addresses that could become vulnerable if quantum computers advance far enough to crack the elliptic curve signatures used by Bitcoin. In comments reported on April 15, Lopp argued that leaving those coins untouched could create a broader market shock if attackers suddenly gained the ability to sweep them. CoinDesk reported that the amount under discussion is about 5.6 million BTC, much of it tied to coins that have not moved in more than a decade.
Lopp has been making the case for months that allowing quantum attackers to seize old bitcoin would not be a neutral outcome, but a forced redistribution of wealth to whoever wins the race to build such machines first. In a March 2025 essay, he wrote that vulnerable coins should be put permanently out of reach rather than left open to what he described as theft. He argued that a large-scale sweep of old wallets could damage trust in Bitcoin and trigger heavy economic disruption if newly captured coins were dumped onto the market.
The position is also reflected in BIP-361, a draft Bitcoin Improvement Proposal co-authored by Lopp and others. The proposal lays out a phased migration to post-quantum protections. Under the draft, Bitcoin would first stop allowing transfers to quantum-vulnerable address types, then later invalidate legacy ECDSA and Schnorr spends after a five-year transition period, effectively freezing coins that were never moved to safer outputs. A third phase, still undefined, would explore whether some legacy funds could be recovered through additional proof mechanisms.
The proposal remains a draft and has no network-wide approval. Bitcoin’s BIP repository makes clear that publication does not mean consensus, adoption, or activation is close. Still, the appearance of BIP-361 has pushed the argument out of theory and into a more formal process, especially as Bitcoin developers and researchers spend more time on post-quantum planning.
