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[2a00:1450:4864:20::133]) by gmr-mx.google.com with ESMTPS id 5b1f17b1804b1-43d1ff8f051si1634695e9.1.2025.03.17.06.28.23 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 Mar 2025 06:28:23 -0700 (PDT) Received-SPF: pass (google.com: domain of jameson.lopp@gmail.com designates 2a00:1450:4864:20::133 as permitted sender) client-ip=2a00:1450:4864:20::133; Received: by mail-lf1-x133.google.com with SMTP id 2adb3069b0e04-5498c742661so4867169e87.1 for ; Mon, 17 Mar 2025 06:28:23 -0700 (PDT) X-Gm-Gg: ASbGncutNAJHul3aGS4F5SPDBNaRP7g9ZFm6NqscksQsXyJ7v/xvPhjLids7pkBR3ca wmmYyIKIJ3XceWXlrbIRCzQP7p7rJFhJjbkovMvcOOy8YKf3QG7dIDxzFYl0FjH5OnfArvlQdR6 2yKKem3olwCjP5BYR4DqtNUKBgMw== X-Received: by 2002:a05:6512:2822:b0:545:a5e:b4ef with SMTP id 2adb3069b0e04-549c38fb956mr7356249e87.16.1742218101717; Mon, 17 Mar 2025 06:28:21 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Jameson Lopp Date: Mon, 17 Mar 2025 09:28:08 -0400 X-Gm-Features: AQ5f1JphJ1NFjSJr2ECc_RDjgMPoeMidR6J9YarWyn82DbMok784MsMZxQVrySM Message-ID: Subject: Re: [bitcoindev] Against Allowing Quantum Recovery of Bitcoin To: IdeA Cc: Bitcoin Development Mailing List Content-Type: multipart/alternative; boundary="0000000000001308a4063089c30d" X-Original-Sender: jameson.lopp@gmail.com X-Original-Authentication-Results: gmr-mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=AVIeup9V; spf=pass (google.com: domain of jameson.lopp@gmail.com designates 2a00:1450:4864:20::133 as permitted sender) smtp.mailfrom=jameson.lopp@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com; dara=pass header.i=@googlegroups.com Precedence: list Mailing-list: list bitcoindev@googlegroups.com; contact bitcoindev+owners@googlegroups.com List-ID: X-Google-Group-Id: 786775582512 List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , X-Spam-Score: 0.0 (/) --0000000000001308a4063089c30d Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable > Could those who, for whatever reason, do not want to migrate to secure addresses be allowed to do so if they sign with their keys, thus providing proof of life and possession, and not participating in this update scheme? While nearly anything is technically possible, I'm skeptical that folks would be sufficiently motivated to build this functionality. Ceasing support for vulnerable software and systems is a common concept. For example, IIRC, Bitcoin Core provides support for 18 months, Ubuntu provides long-term support for 5 years, Windows provides unpaid support for 5 years, etc. https://endoflife.date/ On Sun, Mar 16, 2025 at 6:56=E2=80=AFPM IdeA wrote: > Hi Jameson, Could those who, for whatever reason, do not want to migrate > to secure addresses be allowed to do so if they sign with their keys, thu= s > providing proof of life and possession, and not participating in this > update scheme? This could be a way to not violate the principle of freedo= m > and sovereignty of each individual over their addresses. > > Very interesting article, I completely agree. > > > Sincerely, Fedebuyito. - > > > El El dom, 16 mar 2025 a la(s) 12:22, Jameson Lopp > escribi=C3=B3: > >> The quantum computing debate is heating up. There are many controversial >> aspects to this debate, including whether or not quantum computers will >> ever actually become a practical threat. >> >> I won't tread into the unanswerable question of how worried we should be >> about quantum computers. I think it's far from a crisis, but given the >> difficulty in changing Bitcoin it's worth starting to seriously discuss. >> Today I wish to focus on a philosophical quandary related to one of the >> decisions that would need to be made if and when we implement a quantum >> safe signature scheme. >> >> Several Scenarios >> Because this essay will reference game theory a fair amount, and there >> are many variables at play that could change the nature of the game, I >> think it's important to clarify the possible scenarios up front. >> >> 1. Quantum computing never materializes, never becomes a threat, and thu= s >> everything discussed in this essay is moot. >> 2. A quantum computing threat materializes suddenly and Bitcoin does not >> have quantum safe signatures as part of the protocol. In this scenario i= t >> would likely make the points below moot because Bitcoin would be >> fundamentally broken and it would take far too long to upgrade the >> protocol, wallet software, and migrate user funds in order to restore >> confidence in the network. >> 3. Quantum computing advances slowly enough that we come to consensus >> about how to upgrade Bitcoin and post quantum security has been minimall= y >> adopted by the time an attacker appears. >> 4. Quantum computing advances slowly enough that we come to consensus >> about how to upgrade Bitcoin and post quantum security has been highly >> adopted by the time an attacker appears. >> >> For the purposes of this post, I'm envisioning being in situation 3 or 4= . >> >> To Freeze or not to Freeze? >> I've started seeing more people weighing in on what is likely the most >> contentious aspect of how a quantum resistance upgrade should be handled= in >> terms of migrating user funds. Should quantum vulnerable funds be left o= pen >> to be swept by anyone with a sufficiently powerful quantum computer OR >> should they be permanently locked? >> >> "I don't see why old coins should be confiscated. The better option is t= o >>> let those with quantum computers free up old coins. While this might ha= ve >>> an inflationary impact on bitcoin's price, to use a turn of phrase, the >>> inflation is transitory. Those with low time preference should support >>> returning lost coins to circulation." >> >> - Hunter Beast >> >> >> On the other hand: >> >> "Of course they have to be confiscated. If and when (and that's a big if= ) >>> the existence of a cryptography-breaking QC becomes a credible threat, = the >>> Bitcoin ecosystem has no other option than softforking out the ability = to >>> spend from signature schemes (including ECDSA and BIP340) that are >>> vulnerable to QCs. The alternative is that millions of BTC become >>> vulnerable to theft; I cannot see how the currency can maintain any val= ue >>> at all in such a setting. And this affects everyone; even those which >>> diligently moved their coins to PQC-protected schemes." >>> - Pieter Wuille >> >> >> I don't think "confiscation" is the most precise term to use, as the >> funds are not being seized and reassigned. Rather, what we're really >> discussing would be better described as "burning" - placing the funds *o= ut >> of reach of everyone*. >> >> Not freezing user funds is one of Bitcoin's inviolable properties. >> However, if quantum computing becomes a threat to Bitcoin's elliptic cur= ve >> cryptography, *an inviolable property of Bitcoin will be violated one >> way or another*. >> >> Fundamental Properties at Risk >> 5 years ago I attempted to comprehensively categorize all of Bitcoin's >> fundamental properties that give it value. >> https://nakamoto.com/what-are-the-key-properties-of-bitcoin/ >> >> The particular properties in play with regard to this issue seem to be: >> >> *Censorship Resistance* - No one should have the power to prevent others >> from using their bitcoin or interacting with the network. >> >> *Forward Compatibility* - changing the rules such that certain valid >> transactions become invalid could undermine confidence in the protocol. >> >> *Conservatism* - Users should not be expected to be highly responsive to >> system issues. >> >> As a result of the above principles, we have developed a strong meme >> (kudos to Andreas Antonopoulos) that goes as follows: >> >> Not your keys, not your coins. >> >> >> I posit that the corollary to this principle is: >> >> Your keys, only your coins. >> >> >> A quantum capable entity breaks the corollary of this foundational >> principle. We secure our bitcoin with the mathematical probabilities >> related to extremely large random numbers. Your funds are only secure >> because truly random large numbers should not be guessable or discoverab= le >> by anyone else in the world. >> >> This is the principle behind the motto *vires in numeris* - strength in >> numbers. In a world with quantum enabled adversaries, this principle is >> null and void for many types of cryptography, including the elliptic cur= ve >> digital signatures used in Bitcoin. >> >> Who is at Risk? >> There has long been a narrative that Satoshi's coins and others from the >> Satoshi era of P2PK locking scripts that exposed the public key directly= on >> the blockchain will be those that get scooped up by a quantum "miner." B= ut >> unfortunately it's not that simple. If I had a powerful quantum computer= , >> which coins would I target? I'd go to the Bitcoin rich list and find the >> wallets that have exposed their public keys due to re-using addresses th= at >> have previously been spent from. You can easily find them at >> https://bitinfocharts.com/top-100-richest-bitcoin-addresses.html >> >> Note that a few of these wallets, like Bitfinex / Kraken / Tether, would >> be slightly harder to crack because they are multisig wallets. So a quan= tum >> attacker would need to reverse engineer 2 keys for Kraken or 3 for Bitfi= nex >> / Tether in order to spend funds. But many are single signature. >> >> Point being, it's not only the really old lost BTC that are at risk to a >> quantum enabled adversary, at least at time of writing. If we add a quan= tum >> safe signature scheme, we should expect those wallets to be some of the >> first to upgrade given their incentives. >> >> The Ethical Dilemma: Quantifying Harm >> Which decision results in the most harm? >> >> By making quantum vulnerable funds unspendable we potentially harm some >> Bitcoin users who were not paying attention and neglected to migrate the= ir >> funds to a quantum safe locking script. This violates the "conservativis= m" >> principle stated earlier. On the flip side, we prevent those funds plus = far >> more lost funds from falling into the hands of the few privileged folks = who >> gain early access to quantum computers. >> >> By leaving quantum vulnerable funds available to spend, the same set of >> users who would otherwise have funds frozen are likely to see them stole= n. >> And many early adopters who lost their keys will eventually see their >> unreachable funds scooped up by a quantum enabled adversary. >> >> Imagine, for example, being James Howells, who accidentally threw away a >> hard drive with 8,000 BTC on it, currently worth over $600M USD. He has >> spent a decade trying to retrieve it from the landfill where he knows it= 's >> buried, but can't get permission to excavate. I suspect that, given the >> choice, he'd prefer those funds be permanently frozen rather than fall i= nto >> someone else's possession - I know I would. >> >> Allowing a quantum computer to access lost funds doesn't make those user= s >> any worse off than they were before, however it *would* have a negative >> impact upon everyone who is currently holding bitcoin. >> >> It's prudent to expect significant economic disruption if large amounts >> of coins fall into new hands. Since a quantum computer is going to have = a >> massive up front cost, expect those behind it to desire to recoup their >> investment. We also know from experience that when someone suddenly find= s >> themselves in possession of 9+ figures worth of highly liquid assets, th= ey >> tend to diversify into other things by selling. >> >> Allowing quantum recovery of bitcoin is *tantamount to wealth >> redistribution*. What we'd be allowing is for bitcoin to be >> redistributed from those who are ignorant of quantum computers to those = who >> have won the technological race to acquire quantum computers. It's hard = to >> see a bright side to that scenario. >> >> Is Quantum Recovery Good for Anyone? >> >> Does quantum recovery HELP anyone? I've yet to come across an argument >> that it's a net positive in any way. It certainly doesn't add any securi= ty >> to the network. If anything, it greatly decreases the security of the >> network by allowing funds to be claimed by those who did not earn them. >> >> But wait, you may be thinking, wouldn't quantum "miners" have earned >> their coins by all the work and resources invested in building a quantum >> computer? I suppose, in the same sense that a burglar earns their spoils= by >> the resources they invest into surveilling targets and learning the skil= ls >> needed to break into buildings. What I say "earned" I mean through >> productive mutual trade. >> >> For example: >> >> * Investors earn BTC by trading for other currencies. >> * Merchants earn BTC by trading for goods and services. >> * Miners earn BTC by trading thermodynamic security. >> * Quantum miners don't trade anything, they are vampires feeding upon th= e >> system. >> >> There's no reason to believe that allowing quantum adversaries to recove= r >> vulnerable bitcoin will be of benefit to anyone other than the select fe= w >> organizations that win the technological arms race to build the first su= ch >> computers. Probably nation states and/or the top few largest tech compan= ies. >> >> One could certainly hope that an organization with quantum supremacy is >> benevolent and acts in a "white hat" manner to return lost coins to thei= r >> owners, but that's incredibly optimistic and foolish to rely upon. Such = a >> situation creates an insurmountable ethical dilemma of only recovering l= ost >> bitcoin rather than currently owned bitcoin. There's no way to precisely >> differentiate between the two; anyone can claim to have lost their bitco= in >> but if they have lost their keys then proving they ever had the keys >> becomes rather difficult. I imagine that any such white hat recovery >> efforts would have to rely upon attestations from trusted third parties >> like exchanges. >> >> Even if the first actor with quantum supremacy is benevolent, we must >> assume the technology could fall into adversarial hands and thus think >> adversarially about the potential worst case outcomes. Imagine, for >> example, that North Korea continues scooping up billions of dollars from >> hacking crypto exchanges and decides to invest some of those proceeds in= to >> building a quantum computer for the biggest payday ever... >> >> Downsides to Allowing Quantum Recovery >> Let's think through an exhaustive list of pros and cons for allowing or >> preventing the seizure of funds by a quantum adversary. >> >> Historical Precedent >> Previous protocol vulnerabilities weren=E2=80=99t celebrated as "fair ga= me" but >> rather were treated as failures to be remediated. Treating quantum theft >> differently risks rewriting Bitcoin=E2=80=99s history as a free-for-all = rather than >> a system that seeks to protect its users. >> >> Violation of Property Rights >> Allowing a quantum adversary to take control of funds undermines the >> fundamental principle of cryptocurrency - if you keep your keys in your >> possession, only you should be able to access your money. Bitcoin is bui= lt >> on the idea that private keys secure an individual=E2=80=99s assets, and >> unauthorized access (even via advanced tech) is theft, not a legitimate >> transfer. >> >> Erosion of Trust in Bitcoin >> If quantum attackers can exploit vulnerable addresses, confidence in >> Bitcoin as a secure store of value would collapse. Users and investors r= ely >> on cryptographic integrity, and widespread theft could drive adoption aw= ay >> from Bitcoin, destabilizing its ecosystem. >> >> This is essentially the counterpoint to claiming the burning of >> vulnerable funds is a violation of property rights. While some will >> certainly see it as such, others will find the apathy toward stopping >> quantum theft to be similarly concerning. >> >> Unfair Advantage >> Quantum attackers, likely equipped with rare and expensive technology, >> would have an unjust edge over regular users who lack access to such too= ls. >> This creates an inequitable system where only the technologically elite = can >> exploit others, contradicting Bitcoin=E2=80=99s ethos of decentralized p= ower. >> >> Bitcoin is designed to create an asymmetric advantage for DEFENDING one'= s >> wealth. It's supposed to be impractically expensive for attackers to cra= ck >> the entropy and cryptography protecting one's coins. But now we find >> ourselves discussing a situation where this asymmetric advantage is >> compromised in favor of a specific class of attackers. >> >> Economic Disruption >> Large-scale theft from vulnerable addresses could crash Bitcoin=E2=80=99= s price >> as quantum recovered funds are dumped on exchanges. This would harm all >> holders, not just those directly targeted, leading to broader financial >> chaos in the markets. >> >> Moral Responsibility >> Permitting theft via quantum computing sets a precedent that >> technological superiority justifies unethical behavior. This is essentia= lly >> taking a "code is law" stance in which we refuse to admit that both code >> and laws can be modified to adapt to previously unforeseen situations. >> >> Burning of coins can certainly be considered a form of theft, thus I >> think it's worth differentiating the two different thefts being discusse= d: >> >> 1. self-enriching & likely malicious >> 2. harm prevention & not necessarily malicious >> >> Both options lack the consent of the party whose coins are being burnt o= r >> transferred, thus I think the simple argument that theft is immoral beco= mes >> a wash and it's important to drill down into the details of each. >> >> Incentives Drive Security >> I can tell you from a decade of working in Bitcoin security - the averag= e >> user is lazy and is a procrastinator. If Bitcoiners are given a "drop de= ad >> date" after which they know vulnerable funds will be burned, this pressu= re >> accelerates the adoption of post-quantum cryptography and strengthens >> Bitcoin long-term. Allowing vulnerable users to delay upgrading >> indefinitely will result in more laggards, leaving the network more expo= sed >> when quantum tech becomes available. >> >> Steel Manning >> Clearly this is a complex and controversial topic, thus it's worth >> thinking through the opposing arguments. >> >> Protecting Property Rights >> Allowing quantum computers to take vulnerable bitcoin could potentially >> be spun as a hard money narrative - we care so greatly about not violati= ng >> someone's access to their coins that we allow them to be stolen! >> >> But I think the flip side to the property rights narrative is that >> burning vulnerable coins prevents said property from falling into >> undeserving hands. If the entire Bitcoin ecosystem just stands around an= d >> allows quantum adversaries to claim funds that rightfully belong to othe= r >> users, is that really a "win" in the "protecting property rights" catego= ry? >> It feels more like apathy to me. >> >> As such, I think the "protecting property rights" argument is a wash. >> >> Quantum Computers Won't Attack Bitcoin >> There is a great deal of skepticism that sufficiently powerful quantum >> computers will ever exist, so we shouldn't bother preparing for a >> non-existent threat. Others have argued that even if such a computer was >> built, a quantum attacker would not go after bitcoin because they wouldn= 't >> want to reveal their hand by doing so, and would instead attack other >> infrastructure. >> >> It's quite difficult to quantify exactly how valuable attacking other >> infrastructure would be. It also really depends upon when an entity gain= s >> quantum supremacy and thus if by that time most of the world's systems h= ave >> already been upgraded. While I think you could argue that certain entiti= es >> gaining quantum capability might not attack Bitcoin, it would only delay >> the inevitable - eventually somebody will achieve the capability who >> decides to use it for such an attack. >> >> Quantum Attackers Would Only Steal Small Amounts >> Some have argued that even if a quantum attacker targeted bitcoin, they'= d >> only go after old, likely lost P2PK outputs so as to not arouse suspicio= n >> and cause a market panic. >> >> I'm not so sure about that; why go after 50 BTC at a time when you could >> take 250,000 BTC with the same effort as 50 BTC? This is a classic "zero >> day exploit" game theory in which an attacker knows they have a limited >> amount of time before someone else discovers the exploit and either >> benefits from it or patches it. Take, for example, the recent ByBit atta= ck >> - the highest value crypto hack of all time. Lazarus Group had compromis= ed >> the Safe wallet front end JavaScript app and they could have simply had = it >> reassign ownership of everyone's Safe wallets as they were interacting w= ith >> their wallet. But instead they chose to only specifically target ByBit's >> wallet with $1.5 billion in it because they wanted to maximize their >> extractable value. If Lazarus had started stealing from every wallet, th= ey >> would have been discovered quickly and the Safe web app would likely hav= e >> been patched well before any billion dollar wallets executed the malicio= us >> code. >> >> I think the "only stealing small amounts" argument is strongest for >> Situation #2 described earlier, where a quantum attacker arrives before >> quantum safe cryptography has been deployed across the Bitcoin ecosystem= . >> Because if it became clear that Bitcoin's cryptography was broken AND th= ere >> was nowhere safe for vulnerable users to migrate, the only logical optio= n >> would be for everyone to liquidate their bitcoin as quickly as possible.= As >> such, I don't think it applies as strongly for situations in which we ha= ve >> a migration path available. >> >> The 21 Million Coin Supply Should be in Circulation >> Some folks are arguing that it's important for the "circulating / >> spendable" supply to be as close to 21M as possible and that having a >> significant portion of the supply out of circulation is somehow undesira= ble. >> >> While the "21M BTC" attribute is a strong memetic narrative, I don't >> think anyone has ever expected that it would all be in circulation. It h= as >> always been understood that many coins will be lost, and that's actually >> part of the game theory of owning bitcoin! >> >> And remember, the 21M number in and of itself is not a particularly >> important detail - it's not even mentioned in the whitepaper. What's >> important is that the supply is well known and not subject to change. >> >> Self-Sovereignty and Personal Responsibility >> Bitcoin=E2=80=99s design empowers individuals to control their own wealt= h, free >> from centralized intervention. This freedom comes with the burden of >> securing one's private keys. If quantum computing can break obsolete >> cryptography, the fault lies with users who didn't move their funds to >> quantum safe locking scripts. Expecting the network to shield users from >> their own negligence undermines the principle that you, and not a third >> party, are accountable for your assets. >> >> I think this is generally a fair point that "the community" doesn't owe >> you anything in terms of helping you. I think that we do, however, need = to >> consider the incentives and game theory in play with regard to quantum s= afe >> Bitcoiners vs quantum vulnerable Bitcoiners. More on that later. >> >> Code is Law >> Bitcoin operates on transparent, immutable rules embedded in its >> protocol. If a quantum attacker uses superior technology to derive priva= te >> keys from public keys, they=E2=80=99re not "hacking" the system - they'r= e simply >> following what's mathematically permissible within the current code. >> Altering the protocol to stop this introduces subjective human >> intervention, which clashes with the objective, deterministic nature of >> blockchain. >> >> While I tend to agree that code is law, one of the entire points of laws >> is that they can be amended to improve their efficacy in reducing harm. >> Leaning on this point seems more like a pro-ossification stance that it'= s >> better to do nothing and allow harm to occur rather than take action to >> stop an attack that was foreseen far in advance. >> >> Technological Evolution as a Feature, Not a Bug >> It's well known that cryptography tends to weaken over time and >> eventually break. Quantum computing is just the next step in this >> progression. Users who fail to adapt (e.g., by adopting quantum-resistan= t >> wallets when available) are akin to those who ignored technological >> advancements like multisig or hardware wallets. Allowing quantum theft >> incentivizes innovation and keeps Bitcoin=E2=80=99s ecosystem dynamic, p= unishing >> complacency while rewarding vigilance. >> >> Market Signals Drive Security >> If quantum attackers start stealing funds, it sends a clear signal to th= e >> market: upgrade your security or lose everything. This pressure accelera= tes >> the adoption of post-quantum cryptography and strengthens Bitcoin >> long-term. Coddling vulnerable users delays this necessary evolution, >> potentially leaving the network more exposed when quantum tech becomes >> widely accessible. Theft is a brutal but effective teacher. >> >> Centralized Blacklisting Power >> Burning vulnerable funds requires centralized decision-making - a soft >> fork to invalidate certain transactions. This sets a dangerous precedent >> for future interventions, eroding Bitcoin=E2=80=99s decentralization. If= quantum >> theft is blocked, what=E2=80=99s next - reversing exchange hacks? The sy= stem must >> remain neutral, even if it means some lose out. >> >> I think this could be a potential slippery slope if the proposal was to >> only burn specific addresses. Rather, I'd expect a neutral proposal to b= urn >> all funds in locking script types that are known to be quantum vulnerabl= e. >> Thus, we could eliminate any subjectivity from the code. >> >> Fairness in Competition >> Quantum attackers aren't cheating; they're using publicly available >> physics and math. Anyone with the resources and foresight can build or >> access quantum tech, just as anyone could mine Bitcoin in 2009 with a CP= U. >> Early adopters took risks and reaped rewards; quantum innovators are doi= ng >> the same. Calling it =E2=80=9Cunfair=E2=80=9D ignores that Bitcoin has n= ever promised >> equality of outcome - only equality of opportunity within its rules. >> >> I find this argument to be a mischaracterization because we're not >> talking about CPUs. This is more akin to talking about ASICs, except eac= h >> ASIC costs millions if not billions of dollars. This is out of reach fro= m >> all but the wealthiest organizations. >> >> Economic Resilience >> Bitcoin has weathered thefts before (MTGOX, Bitfinex, FTX, etc) and >> emerged stronger. The market can absorb quantum losses, with unaffected >> users continuing to hold and new entrants buying in at lower prices. Fea= r >> of economic collapse overestimates the impact - the network=E2=80=99s an= tifragility >> thrives on such challenges. >> >> This is a big grey area because we don't know when a quantum computer >> will come online and we don't know how quickly said computers would be a= ble >> to steal bitcoin. If, for example, the first generation of sufficiently >> powerful quantum computers were stealing less volume than the current bl= ock >> reward then of course it will have minimal economic impact. But if they'= re >> taking thousands of BTC per day and bringing them back into circulation, >> there will likely be a noticeable market impact as it absorbs the new >> supply. >> >> This is where the circumstances will really matter. If a quantum attacke= r >> appears AFTER the Bitcoin protocol has been upgraded to support quantum >> resistant cryptography then we should expect the most valuable active >> wallets will have upgraded and the juiciest target would be the 31,000 B= TC >> in the address 12ib7dApVFvg82TXKycWBNpN8kFyiAN1dr which has been dormant >> since 2010. In general I'd expect that the amount of BTC re-entering the >> circulating supply would look somewhat similar to the mining emission >> curve: volume would start off very high as the most valuable addresses a= re >> drained and then it would fall off as quantum computers went down the li= st >> targeting addresses with less and less BTC. >> >> Why is economic impact a factor worth considering? Miners and businesses >> in general. More coins being liquidated will push down the price, which >> will negatively impact miner revenue. Similarly, I can attest from worki= ng >> in the industry for a decade, that lower prices result in less demand fr= om >> businesses across the entire industry. As such, burning quantum vulnerab= le >> bitcoin is good for the entire industry. >> >> Practicality & Neutrality of Non-Intervention >> There=E2=80=99s no reliable way to distinguish =E2=80=9Ctheft=E2=80=9D f= rom legitimate "white >> hat" key recovery. If someone loses their private key and a quantum >> computer recovers it, is that stealing or reclaiming? Policing quantum >> actions requires invasive assumptions about intent, which Bitcoin=E2=80= =99s >> trustless design can=E2=80=99t accommodate. Letting the chips fall where= they may >> avoids this mess. >> >> Philosophical Purity >> Bitcoin rejects bailouts. It=E2=80=99s a cold, hard system where outcome= s reflect >> preparation and skill, not sentimentality. If quantum computing upends t= he >> game, that=E2=80=99s the point - Bitcoin isn=E2=80=99t meant to be safe = or fair in a >> nanny-state sense; it=E2=80=99s meant to be free. Users who lose funds t= o quantum >> attacks are casualties of liberty and their own ignorance, not victims o= f >> injustice. >> >> Bitcoin's DAO Moment >> This situation has some similarities to The DAO hack of an Ethereum smar= t >> contract in 2016, which resulted in a fork to stop the attacker and retu= rn >> funds to their original owners. The game theory is similar because it's = a >> situation where a threat is known but there's some period of time before >> the attacker can actually execute the theft. As such, there's time to >> mitigate the attack by changing the protocol. >> >> It also created a schism in the community around the true meaning of >> "code is law," resulting in Ethereum Classic, which decided to allow the >> attacker to retain control of the stolen funds. >> >> A soft fork to burn vulnerable bitcoin could certainly result in a hard >> fork if there are enough miners who reject the soft fork and continue >> including transactions. >> >> Incentives Matter >> We can wax philosophical until the cows come home, but what are the >> actual incentives for existing Bitcoin holders regarding this decision? >> >> "Lost coins only make everyone else's coins worth slightly more. Think o= f >>> it as a donation to everyone." - Satoshi Nakamoto >> >> >> If true, the corollary is: >> >> "Quantum recovered coins only make everyone else's coins worth less. >>> Think of it as a theft from everyone." - Jameson Lopp >> >> >> Thus, assuming we get to a point where quantum resistant signatures are >> supported within the Bitcoin protocol, what's the incentive to let >> vulnerable coins remain spendable? >> >> * It's not good for the actual owners of those coins. It disincentivizes >> owners from upgrading until perhaps it's too late. >> * It's not good for the more attentive / responsible owners of coins who >> have quantum secured their stash. Allowing the circulating supply to >> balloon will assuredly reduce the purchasing power of all bitcoin holder= s. >> >> Forking Game Theory >> From a game theory point of view, I see this as incentivizing users to >> upgrade their wallets. If you disagree with the burning of vulnerable >> coins, all you have to do is move your funds to a quantum safe signature >> scheme. Point being, I don't see there being an economic majority (or ev= en >> more than a tiny minority) of users who would fight such a soft fork. Wh= y >> expend significant resources fighting a fork when you can just move your >> coins to a new address? >> >> Remember that blocking spending of certain classes of locking scripts is >> a tightening of the rules - a soft fork. As such, it can be meaningfully >> enacted and enforced by a mere majority of hashpower. If miners generall= y >> agree that it's in their best interest to burn vulnerable coins, are oth= er >> users going to care enough to put in the effort to run new node software >> that resists the soft fork? Seems unlikely to me. >> >> How to Execute Burning >> In order to be as objective as possible, the goal would be to announce t= o >> the world that after a specific block height / timestamp, Bitcoin nodes >> will no longer accept transactions (or blocks containing such transactio= ns) >> that spend funds from any scripts other than the newly instituted quantu= m >> safe schemes. >> >> It could take a staggered approach to first freeze funds that are >> susceptible to long-range attacks such as those in P2PK scripts or those >> that exposed their public keys due to previously re-using addresses, but= I >> expect the additional complexity would drive further controversy. >> >> How long should the grace period be in order to give the ecosystem time >> to upgrade? I'd say a minimum of 1 year for software wallets to upgrade.= We >> can only hope that hardware wallet manufacturers are able to implement p= ost >> quantum cryptography on their existing hardware with only a firmware upd= ate. >> >> Beyond that, it will take at least 6 months worth of block space for all >> users to migrate their funds, even in a best case scenario. Though if yo= u >> exclude dust UTXOs you could probably get 95% of BTC value migrated in 1 >> month. Of course this is a highly optimistic situation where everyone is >> completely focused on migrations - in reality it will take far longer. >> >> Regardless, I'd think that in order to reasonably uphold Bitcoin's >> conservatism it would be preferable to allow a 4 year migration window. = In >> the meantime, mining pools could coordinate emergency soft forking logic >> such that if quantum attackers materialized, they could accelerate the >> countdown to the quantum vulnerable funds burn. >> >> Random Tangential Benefits >> On the plus side, burning all quantum vulnerable bitcoin would allow us >> to prune all of those UTXOs out of the UTXO set, which would also clean = up >> a lot of dust. Dust UTXOs are a bit of an annoyance and there has even b= een >> a recent proposal for how to incentivize cleaning them up. >> >> We should also expect that incentivizing migration of the entire UTXO se= t >> will create substantial demand for block space that will sustain a fee >> market for a fairly lengthy amount of time. >> >> In Summary >> While the moral quandary of violating any of Bitcoin's inviolable >> properties can make this a very complex issue to discuss, the game theor= y >> and incentives between burning vulnerable coins versus allowing them to = be >> claimed by entities with quantum supremacy appears to be a much simpler >> issue. >> >> I, for one, am not interested in rewarding quantum capable entities by >> inflating the circulating money supply just because some people lost the= ir >> keys long ago and some laggards are not upgrading their bitcoin wallet's >> security. >> >> We can hope that this scenario never comes to pass, but hope is not a >> strategy. >> >> I welcome your feedback upon any of the above points, and contribution o= f >> any arguments I failed to consider. >> >> -- >> You received this message because you are subscribed to the Google Group= s >> "Bitcoin Development Mailing List" group. >> To unsubscribe from this group and stop receiving emails from it, send a= n >> email to bitcoindev+unsubscribe@googlegroups.com. >> To view this discussion visit >> https://groups.google.com/d/msgid/bitcoindev/CADL_X_cF%3DUKVa7CitXReMq8n= A_4RadCF%3D%3DkU4YG%2B0GYN97P6hQ%40mail.gmail.com >> >> . >> > --=20 You received this message because you are subscribed to the Google Groups "= Bitcoin Development Mailing List" group. To unsubscribe from this group and stop receiving emails from it, send an e= mail to bitcoindev+unsubscribe@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/bitcoindev/= CADL_X_egHyS1K6evGKCwRaVY25jUE7K%2B6UjnDFh261j%2BXan0JQ%40mail.gmail.com. --0000000000001308a4063089c30d Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
> Could those who, for whatever reason= , do not want to migrate to secure addresses be allowed to do so if they si= gn with their keys, thus providing proof of life and possession, and not pa= rticipating in this update scheme?

Whi= le nearly anything is technically possible, I'm skeptical that folks wo= uld be sufficiently motivated to build this functionality.

Ceasing support for vulnerable software and systems is a common co= ncept. For example, IIRC, Bitcoin Core provides support for 18 months, Ubun= tu provides long-term support for 5 years, Windows provides unpaid support = for 5 years, etc.=C2=A0https://endoflif= e.date/

On Sun, Mar 16, 2025 at 6:56=E2=80=AFPM Id= eA <flazarte@gmail.com> wro= te:
Hi Jameson, Could those who, for whatever reason, do not want to migrate to secure addr= esses be allowed to do so if they sign with their keys, thus providing proo= f of life and possession, and not participating in this update scheme? This= could be a way to not violate the principle of freedom and sovereignty of = each individual over their addresses.=C2=A0

Very interesting article, I completely agree.


Since= rely, Fedebuyito. -


El El dom, 16 mar 2025 a la(s) 12:22, Jameson= Lopp <james= on.lopp@gmail.com> escribi=C3=B3:
The quantum computing debate is h= eating up. There are many controversial aspects to this debate, including w= hether or not quantum computers will ever actually become a practical threa= t.

I won't tread into the unanswerable question of how worried = we should be about quantum computers. I think it's far from a crisis, b= ut given the difficulty in changing Bitcoin it's worth starting to seri= ously discuss. Today I wish to focus on a philosophical quandary related to= one of the decisions that would need to be made if and when we implement a= quantum safe signature scheme.

Several Scenarios
Because this essay will reference game = theory a fair amount, and there are many variables at play that could chang= e the nature of the game, I think it's important to clarify the possibl= e scenarios up front.

1. Quantum computing never materializes, never= becomes a threat, and thus everything discussed in this essay is moot.
= 2. A quantum computing threat materializes suddenly and Bitcoin does not ha= ve quantum safe signatures as part of the protocol. In this scenario it wou= ld likely make the points below moot because Bitcoin would be fundamentally= broken and it would take far too long to upgrade the protocol, wallet soft= ware, and migrate user funds in order to restore confidence in the network.=
3. Quantum computing advances slowly enough that we come to consensus a= bout how to upgrade Bitcoin and post quantum security has been minimally ad= opted by the time an attacker appears.
4. Quantum computing advances slo= wly enough that we come to consensus about how to upgrade Bitcoin and post = quantum security has been highly adopted by the time an attacker appears.
For the purposes of this post, I'm envisioning being in situation= 3 or 4.

To Freeze or no= t to Freeze?
I've started seeing more people weighing in on w= hat is likely the most contentious aspect of how a quantum resistance upgra= de should be handled in terms of migrating user funds. Should quantum vulne= rable funds be left open to be swept by anyone with a sufficiently powerful= quantum computer OR should they be permanently locked?

"I don't see why old coins s= hould be confiscated. The better option is to let those with quantum comput= ers free up old coins. While this might have an inflationary impact on bitc= oin's price, to use a turn of phrase, the inflation is transitory. Thos= e with low time preference should support returning lost coins to circulati= on."=C2=A0
- Hunter Beast

On the other hand:
<= br>
"Of course they h= ave to be confiscated. If and when (and that's a big if) the existence = of a cryptography-breaking QC becomes a credible threat, the Bitcoin ecosys= tem has no other option than softforking out the ability to spend from sign= ature schemes (including ECDSA and BIP340) that are vulnerable to QCs. The = alternative is that millions of BTC become vulnerable to theft; I cannot se= e how the currency can maintain any value at all in such a setting. And thi= s affects everyone; even those which diligently moved their coins to PQC-pr= otected schemes."
- Pieter Wuille

I don't think= "confiscation" is the most precise term to use, as the funds are= not being seized and reassigned. Rather, what we're really discussing = would be better described as "burning" - placing the funds out= of reach of everyone.

Not freezing user funds is one of Bitcoin= 's inviolable properties. However, if quantum computing becomes a threa= t to Bitcoin's elliptic curve cryptography, an inviolable property o= f Bitcoin will be violated one way or another.

Fundamental Properties at Risk
5 years= ago I attempted to comprehensively categorize all of Bitcoin's fundame= ntal properties that give it value. https://nakamoto.com/wh= at-are-the-key-properties-of-bitcoin/

The particular properties = in play with regard to this issue seem to be:

Censorship Resistan= ce - No one should have the power to prevent others from using their bi= tcoin or interacting with the network.

Forward Compatibility = - changing the rules such that certain valid transactions become invalid co= uld undermine confidence in the protocol.

Conservatism - User= s should not be expected to be highly responsive to system issues.

A= s a result of the above principles, we have developed a strong meme (kudos = to Andreas Antonopoulos) that goes as follows:

Not your keys, not your coins.
I posit that the corollary to this principle is:

Your keys, only your coins.
A quantum capable entity breaks the corollary of this foundational princi= ple. We secure our bitcoin with the mathematical probabilities related to e= xtremely large random numbers. Your funds are only secure because truly ran= dom large numbers should not be guessable or discoverable by anyone else in= the world.

This is the principle behind the motto vires in numer= is - strength in numbers. In a world with quantum enabled adversaries, = this principle is null and void for many types of cryptography, including t= he elliptic curve digital signatures used in Bitcoin.

Who is at Risk?
There has long been= a narrative that Satoshi's coins and others from the Satoshi era of P2= PK locking scripts that exposed the public key directly on the blockchain w= ill be those that get scooped up by a quantum "miner." But unfort= unately it's not that simple. If I had a powerful quantum computer, whi= ch coins would I target? I'd go to the Bitcoin rich list and find the w= allets that have exposed their public keys due to re-using addresses that h= ave previously been spent from. You can easily find them at https://bitinfocharts.com/top-100-richest-bitcoin-addresses.html
Note that a few of these wallets, like Bitfinex / Kraken / Tether, wo= uld be slightly harder to crack because they are multisig wallets. So a qua= ntum attacker would need to reverse engineer 2 keys for Kraken or 3 for Bit= finex / Tether in order to spend funds. But many are single signature.
<= br>Point being, it's not only the really old lost BTC that are at risk = to a quantum enabled adversary, at least at time of writing. If we add a qu= antum safe signature scheme, we should expect those wallets to be some of t= he first to upgrade given their incentives.

The Ethical Dilemma: Quantifying Harm
Which= decision results in the most harm?

By making quantum vulnerable fun= ds unspendable we potentially harm some Bitcoin users who were not paying a= ttention and neglected to migrate their funds to a quantum safe locking scr= ipt. This violates the "conservativism" principle stated earlier.= On the flip side, we prevent those funds plus far more lost funds from fal= ling into the hands of the few privileged folks who gain early access to qu= antum computers.

By leaving quantum vulnerable funds available to sp= end, the same set of users who would otherwise have funds frozen are likely= to see them stolen. And many early adopters who lost their keys will event= ually see their unreachable funds scooped up by a quantum enabled adversary= .

Imagine, for example, being James Howells, who accidentally threw = away a hard drive with 8,000 BTC on it, currently worth over $600M USD. He = has spent a decade trying to retrieve it from the landfill where he knows i= t's buried, but can't get permission to excavate. I suspect that, g= iven the choice, he'd prefer those funds be permanently frozen rather t= han fall into someone else's possession - I know I would.

Allowi= ng a quantum computer to access lost funds doesn't make those users any= worse off than they were before, however it would have a negative i= mpact upon everyone who is currently holding bitcoin.

It's prude= nt to expect significant economic disruption if large amounts of coins fall= into new hands. Since a quantum computer is going to have a massive up fro= nt cost, expect those behind it to desire to recoup their investment. We al= so know from experience that when someone suddenly finds themselves in poss= ession of 9+ figures worth of highly liquid assets, they tend to diversify = into other things by selling.

Allowing quantum recovery of bitcoin i= s tantamount to wealth redistribution. What we'd be allowing is = for bitcoin to be redistributed from those who are ignorant of quantum comp= uters to those who have won the technological race to acquire quantum compu= ters. It's hard to see a bright side to that scenario.

Is Quantum Recovery Good for Anyone?

Does quantum recovery HELP anyone? I've yet to come across a= n argument that it's a net positive in any way. It certainly doesn'= t add any security to the network. If anything, it greatly decreases the se= curity of the network by allowing funds to be claimed by those who did not = earn them.

But wait, you may be thinking, wouldn't quantum "= ;miners" have earned their coins by all the work and resources investe= d in building a quantum computer? I suppose, in the same sense that a burgl= ar earns their spoils by the resources they invest into surveilling targets= and learning the skills needed to break into buildings. What I say "e= arned" I mean through productive mutual trade.

For example:
=
* Investors earn BTC by trading for other currencies.
* Merchants ea= rn BTC by trading for goods and services.
* Miners earn BTC by trading t= hermodynamic security.
* Quantum miners don't trade anything, they a= re vampires feeding upon the system.

There's no reason to believ= e that allowing quantum adversaries to recover vulnerable bitcoin will be o= f benefit to anyone other than the select few organizations that win the te= chnological arms race to build the first such computers. Probably nation st= ates and/or the top few largest tech companies.

One could certainly = hope that an organization with quantum supremacy is benevolent and acts in = a "white hat" manner to return lost coins to their owners, but th= at's incredibly optimistic and foolish to rely upon. Such a situation c= reates an insurmountable ethical dilemma of only recovering lost bitcoin ra= ther than currently owned bitcoin. There's no way to precisely differen= tiate between the two; anyone can claim to have lost their bitcoin but if t= hey have lost their keys then proving they ever had the keys becomes rather= difficult. I imagine that any such white hat recovery efforts would have t= o rely upon attestations from trusted third parties like exchanges.

= Even if the first actor with quantum supremacy is benevolent, we must assum= e the technology could fall into adversarial hands and thus think adversari= ally about the potential worst case outcomes. Imagine, for example, that No= rth Korea continues scooping up billions of dollars from hacking crypto exc= hanges and decides to invest some of those proceeds into building a quantum= computer for the biggest payday ever...

Downsides to Allowing Quantum Recovery
Let's= think through an exhaustive list of pros and cons for allowing or preventi= ng the seizure of funds by a quantum adversary.

Historical Precedent
Previous protocol vu= lnerabilities weren=E2=80=99t celebrated as "fair game" but rathe= r were treated as failures to be remediated. Treating quantum theft differe= ntly risks rewriting Bitcoin=E2=80=99s history as a free-for-all rather tha= n a system that seeks to protect its users.

Violation of Property Rights
Allowing a qua= ntum adversary to take control of funds undermines the fundamental principl= e of cryptocurrency - if you keep your keys in your possession, only you sh= ould be able to access your money. Bitcoin is built on the idea that privat= e keys secure an individual=E2=80=99s assets, and unauthorized access (even= via advanced tech) is theft, not a legitimate transfer.

Erosion of Trust in Bitcoin
If = quantum attackers can exploit vulnerable addresses, confidence in Bitcoin a= s a secure store of value would collapse. Users and investors rely on crypt= ographic integrity, and widespread theft could drive adoption away from Bit= coin, destabilizing its ecosystem.

This is essentially the counterpo= int to claiming the burning of vulnerable funds is a violation of property = rights. While some will certainly see it as such, others will find the apat= hy toward stopping quantum theft to be similarly concerning.

Unfair Advantage
Quantum att= ackers, likely equipped with rare and expensive technology, would have an u= njust edge over regular users who lack access to such tools. This creates a= n inequitable system where only the technologically elite can exploit other= s, contradicting Bitcoin=E2=80=99s ethos of decentralized power.

Bit= coin is designed to create an asymmetric advantage for DEFENDING one's = wealth. It's supposed to be impractically expensive for attackers to cr= ack the entropy and cryptography protecting one's coins. But now we fin= d ourselves discussing a situation where this asymmetric advantage is compr= omised in favor of a specific class of attackers.

Economic Disruption
Large-scale theft f= rom vulnerable addresses could crash Bitcoin=E2=80=99s price as quantum rec= overed funds are dumped on exchanges. This would harm all holders, not just= those directly targeted, leading to broader financial chaos in the markets= .

Moral Responsibility
Permitting theft via quantum computing sets a precedent that techn= ological superiority justifies unethical behavior. This is essentially taki= ng a "code is law" stance in which we refuse to admit that both c= ode and laws can be modified to adapt to previously unforeseen situations.<= br>
Burning of coins can certainly be considered a form of theft, thus I= think it's worth differentiating the two different thefts being discus= sed:

1. self-enriching & likely malicious
2. harm prevention = & not necessarily malicious

Both options lack the consent of the= party whose coins are being burnt or transferred, thus I think the simple = argument that theft is immoral becomes a wash and it's important to dri= ll down into the details of each.

Incentives Drive Security
I can tell you from a decade = of working in Bitcoin security - the average user is lazy and is a procrast= inator. If Bitcoiners are given a "drop dead date" after which th= ey know vulnerable funds will be burned, this pressure accelerates the adop= tion of post-quantum cryptography and strengthens Bitcoin long-term. Allowi= ng vulnerable users to delay upgrading indefinitely will result in more lag= gards, leaving the network more exposed when quantum tech becomes available= .

Steel Manning
Clearly this is a complex and controversial topic, thus it's worth th= inking through the opposing arguments.

Protecting Property Rights
Allowing quantum comput= ers to take vulnerable bitcoin could potentially be spun as a hard money na= rrative - we care so greatly about not violating someone's access to th= eir coins that we allow them to be stolen!

But I think the flip side= to the property rights narrative is that burning vulnerable coins prevents= said property from falling into undeserving hands. If the entire Bitcoin e= cosystem just stands around and allows quantum adversaries to claim funds t= hat rightfully belong to other users, is that really a "win" in t= he "protecting property rights" category? It feels more like apat= hy to me.

As such, I think the "protecting property rights"= ; argument is a wash.

Qu= antum Computers Won't Attack Bitcoin
There is a great deal of= skepticism that sufficiently powerful quantum computers will ever exist, s= o we shouldn't bother preparing for a non-existent threat. Others have = argued that even if such a computer was built, a quantum attacker would not= go after bitcoin because they wouldn't want to reveal their hand by do= ing so, and would instead attack other infrastructure.

It's quit= e difficult to quantify exactly how valuable attacking other infrastructure= would be. It also really depends upon when an entity gains quantum suprema= cy and thus if by that time most of the world's systems have already be= en upgraded. While I think you could argue that certain entities gaining qu= antum capability might not attack Bitcoin, it would only delay the inevitab= le - eventually somebody will achieve the capability who decides to use it = for such an attack.

Quan= tum Attackers Would Only Steal Small Amounts
Some have argued tha= t even if a quantum attacker targeted bitcoin, they'd only go after old= , likely lost P2PK outputs so as to not arouse suspicion and cause a market= panic.

I'm not so sure about that; why go after 50 BTC at a tim= e when you could take 250,000 BTC with the same effort as 50 BTC? This is a= classic "zero day exploit" game theory in which an attacker know= s they have a limited amount of time before someone else discovers the expl= oit and either benefits from it or patches it. Take, for example, the recen= t ByBit attack - the highest value crypto hack of all time. Lazarus Group h= ad compromised the Safe wallet front end JavaScript app and they could have= simply had it reassign ownership of everyone's Safe wallets as they we= re interacting with their wallet. But instead they chose to only specifical= ly target ByBit's wallet with $1.5 billion in it because they wanted to= maximize their extractable value. If Lazarus had started stealing from eve= ry wallet, they would have been discovered quickly and the Safe web app wou= ld likely have been patched well before any billion dollar wallets executed= the malicious code.

I think the "only stealing small amounts&q= uot; argument is strongest for Situation #2 described earlier, where a quan= tum attacker arrives before quantum safe cryptography has been deployed acr= oss the Bitcoin ecosystem. Because if it became clear that Bitcoin's cr= yptography was broken AND there was nowhere safe for vulnerable users to mi= grate, the only logical option would be for everyone to liquidate their bit= coin as quickly as possible. As such, I don't think it applies as stron= gly for situations in which we have a migration path available.

The 21 Million Coin Supply Should b= e in Circulation
Some folks are arguing that it's important f= or the "circulating / spendable" supply to be as close to 21M as = possible and that having a significant portion of the supply out of circula= tion is somehow undesirable.

While the "21M BTC" attribute= is a strong memetic narrative, I don't think anyone has ever expected = that it would all be in circulation. It has always been understood that man= y coins will be lost, and that's actually part of the game theory of ow= ning bitcoin!

And remember, the 21M number in and of itself is not a= particularly important detail - it's not even mentioned in the whitepa= per. What's important is that the supply is well known and not subject = to change.

Self-Sovereig= nty and Personal Responsibility
Bitcoin=E2=80=99s design empowers= individuals to control their own wealth, free from centralized interventio= n. This freedom comes with the burden of securing one's private keys. I= f quantum computing can break obsolete cryptography, the fault lies with us= ers who didn't move their funds to quantum safe locking scripts. Expect= ing the network to shield users from their own negligence undermines the pr= inciple that you, and not a third party, are accountable for your assets.
I think this is generally a fair point that "the community"= doesn't owe you anything in terms of helping you. I think that we do, = however, need to consider the incentives and game theory in play with regar= d to quantum safe Bitcoiners vs quantum vulnerable Bitcoiners. More on that= later.

Code is Law
Bitcoin operates on transparent, immutable rules embedded in its prot= ocol. If a quantum attacker uses superior technology to derive private keys= from public keys, they=E2=80=99re not "hacking" the system - the= y're simply following what's mathematically permissible within the = current code. Altering the protocol to stop this introduces subjective huma= n intervention, which clashes with the objective, deterministic nature of b= lockchain.

While I tend to agree that code is law, one of the entire= points of laws is that they can be amended to improve their efficacy in re= ducing harm. Leaning on this point seems more like a pro-ossification stanc= e that it's better to do nothing and allow harm to occur rather than ta= ke action to stop an attack that was foreseen far in advance.

Technological Evolution as a Feature,= Not a Bug
It's well known that cryptography tends to weaken = over time and eventually break. Quantum computing is just the next step in = this progression. Users who fail to adapt (e.g., by adopting quantum-resist= ant wallets when available) are akin to those who ignored technological adv= ancements like multisig or hardware wallets. Allowing quantum theft incenti= vizes innovation and keeps Bitcoin=E2=80=99s ecosystem dynamic, punishing c= omplacency while rewarding vigilance.

Market Signals Drive Security
If quantum attackers = start stealing funds, it sends a clear signal to the market: upgrade your s= ecurity or lose everything. This pressure accelerates the adoption of post-= quantum cryptography and strengthens Bitcoin long-term. Coddling vulnerable= users delays this necessary evolution, potentially leaving the network mor= e exposed when quantum tech becomes widely accessible. Theft is a brutal bu= t effective teacher.

Cen= tralized Blacklisting Power
Burning vulnerable funds requires cen= tralized decision-making - a soft fork to invalidate certain transactions. = This sets a dangerous precedent for future interventions, eroding Bitcoin= =E2=80=99s decentralization. If quantum theft is blocked, what=E2=80=99s ne= xt - reversing exchange hacks? The system must remain neutral, even if it m= eans some lose out.

I think this could be a potential slippery slope= if the proposal was to only burn specific addresses. Rather, I'd expec= t a neutral proposal to burn all funds in locking script types that are kno= wn to be quantum vulnerable. Thus, we could eliminate any subjectivity from= the code.

Fairness in C= ompetition
Quantum attackers aren't cheating; they're usi= ng publicly available physics and math. Anyone with the resources and fores= ight can build or access quantum tech, just as anyone could mine Bitcoin in= 2009 with a CPU. Early adopters took risks and reaped rewards; quantum inn= ovators are doing the same. Calling it =E2=80=9Cunfair=E2=80=9D ignores tha= t Bitcoin has never promised equality of outcome - only equality of opportu= nity within its rules.

I find this argument to be a mischaracterizat= ion because we're not talking about CPUs. This is more akin to talking = about ASICs, except each ASIC costs millions if not billions of dollars. Th= is is out of reach from all but the wealthiest organizations.

Economic Resilience
Bitcoin= has weathered thefts before (MTGOX, Bitfinex, FTX, etc) and emerged strong= er. The market can absorb quantum losses, with unaffected users continuing = to hold and new entrants buying in at lower prices. Fear of economic collap= se overestimates the impact - the network=E2=80=99s antifragility thrives o= n such challenges.

This is a big grey area because we don't know= when a quantum computer will come online and we don't know how quickly= said computers would be able to steal bitcoin. If, for example, the first = generation of sufficiently powerful quantum computers were stealing less vo= lume than the current block reward then of course it will have minimal econ= omic impact. But if they're taking thousands of BTC per day and bringin= g them back into circulation, there will likely be a noticeable market impa= ct as it absorbs the new supply.

This is where the circumstances wil= l really matter. If a quantum attacker appears AFTER the Bitcoin protocol h= as been upgraded to support quantum resistant cryptography then we should e= xpect the most valuable active wallets will have upgraded and the juiciest = target would be the 31,000 BTC in the address 12ib7dApVFvg82TXKycWBNpN8kFyi= AN1dr which has been dormant since 2010. In general I'd expect that the= amount of BTC re-entering the circulating supply would look somewhat simil= ar to the mining emission curve: volume would start off very high as the mo= st valuable addresses are drained and then it would fall off as quantum com= puters went down the list targeting addresses with less and less BTC.
Why is economic impact a factor worth considering? Miners and businesses = in general. More coins being liquidated will push down the price, which wil= l negatively impact miner revenue. Similarly, I can attest from working in = the industry for a decade, that lower prices result in less demand from bus= inesses across the entire industry. As such, burning quantum vulnerable bit= coin is good for the entire industry.

Practicality & Neutrality of Non-Intervention
T= here=E2=80=99s no reliable way to distinguish =E2=80=9Ctheft=E2=80=9D from = legitimate "white hat" key recovery. If someone loses their priva= te key and a quantum computer recovers it, is that stealing or reclaiming? = Policing quantum actions requires invasive assumptions about intent, which = Bitcoin=E2=80=99s trustless design can=E2=80=99t accommodate. Letting the c= hips fall where they may avoids this mess.

Philosophical Purity
Bitcoin rejects bailouts.= It=E2=80=99s a cold, hard system where outcomes reflect preparation and sk= ill, not sentimentality. If quantum computing upends the game, that=E2=80= =99s the point - Bitcoin isn=E2=80=99t meant to be safe or fair in a nanny-= state sense; it=E2=80=99s meant to be free. Users who lose funds to quantum= attacks are casualties of liberty and their own ignorance, not victims of = injustice.

Bitcoin's= DAO Moment
This situation has some similarities to The DAO hack = of an Ethereum smart contract in 2016, which resulted in a fork to stop the= attacker and return funds to their original owners. The game theory is sim= ilar because it's a situation where a threat is known but there's s= ome period of time before the attacker can actually execute the theft. As s= uch, there's time to mitigate the attack by changing the protocol.
<= br>It also created a schism in the community around the true meaning of &qu= ot;code is law," resulting in Ethereum Classic, which decided to allow= the attacker to retain control of the stolen funds.

A soft fork to = burn vulnerable bitcoin could certainly result in a hard fork if there are = enough miners who reject the soft fork and continue including transactions.=

Incentives Matter
We can wax philosophical until the cows come home, but what are the ac= tual incentives for existing Bitcoin holders regarding this decision?
"Lost coins only m= ake everyone else's coins worth slightly more. Think of it as a donatio= n to everyone." - Satoshi Nakamoto

If true, the coroll= ary is:

"Quan= tum recovered coins only make everyone else's coins worth less. Think o= f it as a theft from everyone." - Jameson Lopp

Thus, a= ssuming we get to a point where quantum resistant signatures are supported = within the Bitcoin protocol, what's the incentive to let vulnerable coi= ns remain spendable?

* It's not good for the actual owners of th= ose coins. It disincentivizes owners from upgrading until perhaps it's = too late.
* It's not good for the more attentive / responsible owner= s of coins who have quantum secured their stash. Allowing the circulating s= upply to balloon will assuredly reduce the purchasing power of all bitcoin = holders.

Forking Game Th= eory
From a game theory point of view, I see this as incentivizin= g users to upgrade their wallets. If you disagree with the burning of vulne= rable coins, all you have to do is move your funds to a quantum safe signat= ure scheme. Point being, I don't see there being an economic majority (= or even more than a tiny minority) of users who would fight such a soft for= k. Why expend significant resources fighting a fork when you can just move = your coins to a new address?

Remember that blocking spending of cert= ain classes of locking scripts is a tightening of the rules - a soft fork. = As such, it can be meaningfully enacted and enforced by a mere majority of = hashpower. If miners generally agree that it's in their best interest t= o burn vulnerable coins, are other users going to care enough to put in the= effort to run new node software that resists the soft fork? Seems unlikely= to me.

How to Execute B= urning
In order to be as objective as possible, the goal would be= to announce to the world that after a specific block height / timestamp, B= itcoin nodes will no longer accept transactions (or blocks containing such = transactions) that spend funds from any scripts other than the newly instit= uted quantum safe schemes.

It could take a staggered approach to fir= st freeze funds that are susceptible to long-range attacks such as those in= P2PK scripts or those that exposed their public keys due to previously re-= using addresses, but I expect the additional complexity would drive further= controversy.

How long should the grace period be in order to give t= he ecosystem time to upgrade? I'd say a minimum of 1 year for software = wallets to upgrade. We can only hope that hardware wallet manufacturers are= able to implement post quantum cryptography on their existing hardware wit= h only a firmware update.

Beyond that, it will take at least 6 month= s worth of block space for all users to migrate their funds, even in a best= case scenario. Though if you exclude dust UTXOs you could probably get 95%= of BTC value migrated in 1 month. Of course this is a highly optimistic si= tuation where everyone is completely focused on migrations - in reality it = will take far longer.

Regardless, I'd think that in order to rea= sonably uphold Bitcoin's conservatism it would be preferable to allow a= 4 year migration window. In the meantime, mining pools could coordinate em= ergency soft forking logic such that if quantum attackers materialized, the= y could accelerate the countdown to the quantum vulnerable funds burn.
<= br>Random Tangential Benefits
On the plus side, burning all quantum vulnerable bitcoin would all= ow us to prune all of those UTXOs out of the UTXO set, which would also cle= an up a lot of dust. Dust UTXOs are a bit of an annoyance and there has eve= n been a recent proposal for how to incentivize cleaning them up.

We= should also expect that incentivizing migration of the entire UTXO set wil= l create substantial demand for block space that will sustain a fee market = for a fairly lengthy amount of time.

In Summary
While the moral quandary of violating any= of Bitcoin's inviolable properties can make this a very complex issue = to discuss, the game theory and incentives between burning vulnerable coins= versus allowing them to be claimed by entities with quantum supremacy appe= ars to be a much simpler issue.

I, for one, am not interested in rew= arding quantum capable entities by inflating the circulating money supply j= ust because some people lost their keys long ago and some laggards are not = upgrading their bitcoin wallet's security.

We can hope that this= scenario never comes to pass, but hope is not a strategy.

I welcome= your feedback upon any of the above points, and contribution of any argume= nts I failed to consider.

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