{"id":13222,"date":"2026-09-14T17:19:26","date_gmt":"2026-09-14T17:19:26","guid":{"rendered":"https:\/\/cryptonews.uk.com\/?p=13222"},"modified":"2026-09-14T17:19:26","modified_gmt":"2026-09-14T17:19:26","slug":"bitcoin-exchanges-can-reduce-quantum-exposure-before-a-network-upgrade","status":"publish","type":"post","link":"https:\/\/cryptonews.uk.com\/?p=13222","title":{"rendered":"Bitcoin exchanges can reduce quantum exposure before a network upgrade"},"content":{"rendered":"

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A future quantum-safe Bitcoin will have to pass through the systems that hold and move today’s coins. Exchanges, institutional custodians, hardware wallets and key-management platforms would all need to adopt new rules while continuing to process deposits, withdrawals, approvals, backups and recoveries.<\/p>\n

That operational challenge moved to the center of the debate after Coinbase published a September 9 account of a post-quantum Bitcoin workshop it hosted with Stanford and Localhost Research. Coinbase said the closed-door session brought together developers, cryptographers, institutional custodians and hardware-wallet experts. Participants reached no consensus on an exact post-quantum approach and identified open tradeoffs involving transaction size, hardware performance, key management and adoption.<\/p>\n

An earlier Glassnode exposure study gives that rollout problem a measurable scale. Its May data placed roughly 1.6 million BTC in exchange-related outputs whose public keys were already visible on-chain.<\/p>\n

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Related Reading<\/span><\/p>\n

Bitcoin quantum computing risk centers on major exchange wallets, Glassnode data shows<\/h3>\n<\/p>\n

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A visible public key is not a present theft condition. Sources published through September described no cryptographically relevant quantum computer capable of breaking Bitcoin’s signatures, and Coinbase called the risk non-immediate. The measurement instead identifies coins that a sufficiently capable future machine could target without waiting for their owners to spend.<\/p>\n

A 1.6 million BTC custody cohort<\/h2>\n

Bitcoin signatures allow the network to verify that a spender controls a private key. Conventional computers cannot feasibly derive that private key from its public counterpart. Shor’s algorithm running on a sufficiently capable quantum computer could, in principle, break that assumption.<\/p>\n

Public-key visibility therefore divides the risk into two time windows. An at-rest, or long-exposure, attack would target a key that has remained visible on-chain. A short-exposure attack would target a key revealed only after a transaction enters the mempool, giving an attacker a brief window before confirmation.<\/p>\n

Glassnode estimated that 6.04 million BTC, or 30.2% of issued supply, had public-key exposure at rest in May. The firm classified 1.92 million BTC as structurally exposed because the output type reveals a key or equivalent by design. It attributed 4.12 million BTC, or 20.6%, to operational behavior such as address reuse or leaving a balance associated with a key after a spend revealed it.<\/p>\n

Exchange-related balances were the largest labeled part of that operational bucket. Glassnode’s summary gives 1.63 million BTC, or 8.1% of supply, while its detailed section gives 1.66 million BTC, or 8.3%. Those two slices support a shared description of roughly 1.6 million BTC, equal to about 40% of the study’s operationally exposed total.<\/p>\n

The label has limits. Glassnode presented exchanges as an attributed subset of on-chain balances rather than an exhaustive inventory, and it cautioned against reading the data as a security, solvency or immediate-risk ranking. The results also varied widely: Coinbase-attributed balances showed 5% exposure under the methodology, while several peers showed much higher shares. Custody scale alone did not determine exposure.<\/p>\n

Active control gives exchanges tools that dormant holders lack. Glassnode said address hygiene, change-output rotation and reserve management could shrink operational exposure before Bitcoin adopts a post-quantum signature scheme. A custodian still has to coordinate policies, approvals, backups, deposit addresses and withdrawals, yet it can decide to move a controlled balance.<\/p>\n

Dormant and lost-key coins sit at the opposite end of that spectrum. A March Google Quantum AI paper separated active holdings that can migrate from abandoned or inaccessible assets whose owners cannot produce a valid transaction. Protocol changes can create a safer destination, but they cannot make an absent keyholder sign.<\/p>\n

That distinction turns the exchange pool into a large test of execution rather than a verdict on the hardest part of migration.<\/p>\n\n\n\n\n\n\n\n\n
Workstream<\/th>\nCurrent evidence<\/th>\nRemaining work<\/th>\n<\/tr>\n<\/thead>\n
Long-exposure reduction<\/td>\nAddress hygiene can reduce operational exposure<\/td>\nMove existing balances and deploy safer output types<\/td>\n<\/tr>\n
Short-exposure protection<\/td>\nCandidate post-quantum signatures are being studied<\/td>\nChoose, integrate and activate a scheme<\/td>\n<\/tr>\n
Custody deployment<\/td>\nDevice benchmarks and an MPC simulation show bounded feasibility<\/td>\nValidate production controls, backups and interoperability<\/td>\n<\/tr>\n
Dormant holdings<\/td>\nExposure can be measured<\/td>\nResolve assets that cannot voluntarily migrate<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\"Bitcoin\"Bitcoin<\/p>\n

BIP-360 opens a path while operations catch up<\/h2>\n

BIP-360 separates long-exposure mitigation from the choice of a post-quantum signature. The draft Bitcoin Improvement Proposal would add Pay-to-Merkle-Root, or P2MR, as a new SegWit output through a soft fork.<\/p>\n