后量子代币化：迁移挑战

Global Quantumcomputingdoes notposean immediatethreattoblockchain cryptography, but it could do so in the future HeadofDigital AssetsResearch,SrFX StrategistHSBC Bank plc+44 20 79918888Ella Hewitt + Defences against the quantum computing threat already existsothechallengeisoperationalmigration,nottech Digital Assets AnalystHSBC Bank plcella.hewitt@hsbc.com074687 05070Anirudh Shreevatsa +Tokenised Trad-Fi and stablecoins may be better placed thancrypto forthis migration, but all elements need to move AssociateBangalore automated settlementacross stablecoins,tokenised deposits,tokenised securities,custody platforms and atomic settlement systems.That shift places cryptographycloser to the centre of trust than in traditional market structures,where ownership isreinforcedbylayersofintermediaries,legalagreementsandoperationalcontrolsQuantumcomputingmattersinthiscontextbecausefinancial infrastructureisbuilttolast for decades,meaning systems designed now may still be running in the 2040sand may need to withstand changes in cryptographic assumptions over their lifetime. The primary quantum exposure sits in publickey cryptography (digital signatures andkey-based ownership). A sufficiently capable quantum computer could potentiallyderive a private key from a public key and produce valid signatures, underminingcryptographic ownership.A further, often underweighted risk lies outside the ledgeralsobecompromisedbyapowerful quantum adversary. (CRQC)does not currently exist. Expert views on timelines as to when a CRQCmight arrive are varied but many attach a high likelihood to a 15-year horizon. Inaddition,post-quantum cryptography already exists.So, the hard part is operationalmigration and “cryptographic agility" (the ability to swap cryptographic componentswithout breaking ownership, settlement, or trust). One ofthebiggest mistakes indiscussions about quantum computing is treating alldigital assets as if they face identical risks. They do not. The transition challengevaries by system architecture: public permissionless networks (e.g., Bitcoin)face thetoughestcoordinationproblem;centralisedstablecoinissuerscanmovefasterbutconcentrate operational risk in privileged keys; permissioned and TradFi-ledplatforms may be best positioned operationally but still depend on cross-industryinteroperabilityandcommonstandards.Intheend,overall resiliencehingesonecosystemcoordinationacrossissuers,custodiansinfrastructures,wallets,technology providers and regulators, because trust in tokenised finance is collectiveand a single quantum-vulnerable component can undermine confidence across theentire ecosystem. Issuer of report: HSBC Bank plc Disclosures&Disclaimer This report must be read with the disclosures and the analyst certifications inthe Disclosure appendix, and with the Disclaimer, which forms part of it. ViewHSBC Global Investment Researchat:https://www.research.hsbc.com INTERNAL thedebatefocusesonBitcoin,which is understandable.Afterall, Bitcoinis thelargestdigitalasset, its cryptography is visible to everyone, and its decentralised governance makes majorupgrades difficult. However, focusing solely on Bitcoin misses the larger story.The real issue iswhat quantum computing means for the broader effort to modernise financial markets throughtokenisation.Stablecoins,tokeniseddeposits,tokenisedsecurities,digitalassetcustodymore directly than traditional financial infrastructure.Quantumcomputersdonotposeanimmediatethreat.Noquantumcomputertodaycanbreak quantum computing meansforthebroaderefforttomodernisefinancialmarketsthroughtokenisation builtfordecadesnotyears.Thismeansthatsystemsbeingdesignedtodaymaystill beduringtheirlifetime,thatbecomes an infrastructuredesignheadache pose an immediate threat settlement. In traditional finance, ownership is protected by multiple layers of intermediaries,legal agreements and operational controls.In tokenised systems,ownership is often moreclosely linked to possession of a cryptographic key. That creates efficiencies but it may alsocreate new forms of vulnerability. Quantum computing is unlikely to destroy digital assets, so the key is whether the nextgeneration of financial infrastructure is being designed with sufficient flexibility to adapt ifcryptographic assumptions change. Anon-technicalexplainer:whatquantumcomputingchanges Most tokenised blockchain-based financial systems rely on two broad categories ofcryptography 1.Hashing. Hash functions take information and transform it into a unique digital fingerprint.They are widely used throughout blockchain systems. Hashing helps link blocks together,verify information and maintain the integrity of records. Any amount of data can be changedinto a string of numbers and letters of fixed length, called a hash. Even a modest change tothedatacreatesacompletelydifferenthash.Itiseffectivelyimpossibletoworkoutwhattheoriginal data was from a hash. 2.primary focus of quantum-related concerns. In public key cryptography, every wallet isnum