Bitcoin’s defense against a future of quantum threats is moving from theoretical caution to concrete planning, according to Adam Back, the CEO of Blockstream and a veteran figure in the Bitcoin space. Speaking at Paris Blockchain Week, Back urged the ecosystem to begin building quantum-resistant options now, even as the current threat remains largely in the realm of long-term speculation.

Back argued that quantum computing has a long way to go before posing a real, practical danger to Bitcoin’s cryptography. “Quantum computing still has a lot to prove. Current systems are essentially lab experiments. I’ve followed the field for over 25 years, and progress has been incremental,” he said. Yet, he emphasized that Bitcoin should prepare with a cautious, staged approach—favoring optional upgrades that enable a migration to quantum-resistant cryptography if and when needed.

While many in the industry still view the threat as decades away, the discussion has intensified as researchers reexamine how quickly quantum capabilities could evolve. The conversation sits alongside ongoing debates about how to safeguard wallets and networks should quantum computers become capable of breaking current cryptographic protections. Back’s remarks come with a broader push across the industry to consider a measured, upgrade-ready path rather than waiting for a crisis to force change.

Back’s stance on readiness is complemented by his ongoing work at Blockstream, which has a dedicated quantum-focused team investigating potential threat vectors to Bitcoin. As part of that research, Back highlighted efforts to deploy hash-based signatures on Blockstream’s Bitcoin layer-2 Liquid Network, describing it as a practical step toward resilience while preserving compatibility with existing Bitcoin users.

Preparation is key. Making changes in a controlled way is far safer than reacting in a crisis.

He also noted that the Taproot upgrade could accommodate alternative signature schemes on the Bitcoin network without disrupting current users, suggesting a pathway for gradual adoption rather than disruptive overhauls.

Key takeaways

• Quantum risk is not imminent in the eyes of all observers, but proactive preparedness is gaining ground. Back reiterates a decades-long horizon, yet urges a structured upgrade plan rather than waiting for a crisis.
• Concrete steps are being explored at the protocol and layer-2 level, including hash-based signatures on Liquid and potential signature-scheme diversification under Taproot, to diversify risk without breaking existing wallets.
• Analysts and researchers are racing to quantify risk, with recent comments tying the pace of quantum advancement to broader industry readiness. The conversation weighs the balance between early action and avoiding unnecessary disruption.
• The discussion around how to treat quantum-vulnerable coins has sparked heated debate within the community, highlighting tensions between safety measures and user rights in governance decisions.
• Developers acknowledge the possibility that, if quantum capabilities materialize sooner than expected, the Bitcoin community would act quickly to adapt, drawing on past experience where urgent bug fixes spurred rapid consensus.

Quantum risk and Bitcoin’s evolving blueprint

The quantum threat has reemerged in public discourse as researchers revisit the speed at which cryptographic protections could be undermined. Last month, Google and California Institute of Technology researchers suggested that functional quantum computers could arrive sooner than previously anticipated and that far less computational power might be required to break cryptography than once thought. Google even raised the prospect that quantum machines could potentially break Bitcoin’s cryptography within minutes, enabling an “on-spend” attack if wallets were exposed to quantum-enabled fraud.

In response, Back signaled that Bitcoin developers would pivot quickly if the risk materialized. “We’ve seen that before — bugs have been identified and fixed within hours. When something becomes urgent, it focuses attention and drives consensus,” he said. This sentiment underscores a broader industry pattern: readiness is valuable not because a threat is immediate, but because it concentrates efforts and accelerates cooperative problem-solving.

Beyond the research community, the discussion has a practical roadmap dimension. At the protocol level, Taproot’s design is seen as offering flexibility for introducing alternative cryptographic schemes without forcing a hard fork or disrupting current users. On the layer-2 front, Liquid Network has begun to test hash-based signatures to diversify post-quantum risk vectors without removing the option for existing Bitcoin transactions to operate as they do today.

Contested ideas: freezing quantum-vulnerable coins

The quantum risk debate recently intensified with a proposal from Bitcoin developer Jameson Lopp and five other security researchers to freeze quantum-vulnerable Bitcoin — including holdings associated with Satoshi Nakamoto’s estimated stash — to prevent theft once quantum computers become functional. The proposal, known as BIP-361, aims to preemptively shield funds by halting transferability of coins deemed at risk from quantum exploitation.

Reaction within the community was swift and critical. Critics described the idea as authoritarian and confiscatory, arguing it would amount to stealing property to avert potential future losses. Others voiced concern that such a mechanism could set dangerous precedents for governance over personal holdings, complicating trust and property rights within a decentralized system. Supporters, however, contended that a well-designed framework could avert catastrophic losses should quantum-era theft become feasible, highlighting the trade-off between security and autonomy.

The broader takeaway is that even technical debates on upgrading cryptographic primitives can quickly unfold into governance questions. As the community weighs options—ranging from soft-fork migrations to controlled asset freezes—participants emphasize the need for transparent, consensus-driven processes that align with Bitcoin’s long-term security goals.

What lies ahead for investors and builders

The unfolding discussions around quantum preparedness carry practical implications for miners, developers, and users alike. For investors, the cadence of progress toward quantum-resilient primitives can affect risk management and discount rates applied to long-horizon cash flows tied to network security. For developers, the emphasis on optional upgrades suggests a preference for modular, non-disruptive paths that preserve user experience while expanding the cryptographic toolkit. For users, the core message is that upgrades should be deployable in a manner that minimizes the need to resecure funds or alter behavior dramatically.

Market participants are watching whether Bitcoin’s governance mechanism can reach broad agreement on a path that balances resilience with decentralization. As Back and others advocate, the most robust strategy may be to embed migration options within existing constructs, allowing the network to evolve gradually without forcing abrupt changes on holders who may be unaffected by early-stage testing.

Looking ahead, the key questions are clear: How quickly will quantum research translate into practical defense mechanisms? Will Taproot’s flexibility prove sufficient for a seamless upgrade path, or will new cryptographic approaches require more substantial protocol changes? And how will the community reconcile urgent risk mitigation with the core ethos of permissionless innovation?

Readers should keep an eye on progress in post-quantum cryptography research, ongoing experiments on Layer-2 solutions, and any governance milestones that define how and when Bitcoin could adopt quantum-resistant technologies. While the threat remains uncertain in its timing, the consensus-building process around upgrades is already shaping the next phase of Bitcoin’s security architecture.

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Sandwich attacks cost Ethereum users an estimated $60 million per year. Transactions broadcast to the public mempool are publicly visible before inclusion, which gives MEV bots the ability to affect the order of transactions and insert their own for profit. This problem has persisted on some level in spite of years of discussion and various out-of-protocol mitigation attempts.

Encrypting mempool transactions would be one of the most compelling solutions to prevent MEV. While this idea has been actively discussed for years, it has not yet been implemented at the protocol level. In our earlier research, we examined several proposals based on threshold-encryption, including Shutter, Batched Threshold Encryption, and Flash Freezing Flash Boys. In this article, we turn to a meta proposal titled “Universal Enshrined Encrypted Mempool (EIP-8105)“.

How EIP-8105 approaches mempool encryption

Universal Enshrined Encrypted Mempool, also known as EIP-8105, is a scheme-agnostic encrypted mempool design, which means it can support a wide range of encryption methods, including threshold encryption, MPC committees, TEEs, delay encryption, and fully homomorphic encryption. A new system contract on the execution layer, called the key provider registry, is planned to facilitate this flexible design. It would allow any account to register as a key provider that holds and reveals decryption keys using their own preferred encryption technology. 

How transactions are executed in Universal Enshrined Encrypted Mempool

Universal Enshrined Encrypted Mempool introduces two new transaction types under the EIP-2718 framework: 0x05 for encrypted transactions and 0x06 for decrypted transactions. An encrypted transaction is an envelope with an encrypted payload and a public payload, which contains the envelope nonce, gas amount, gas price parameters, key provider ID, key ID, and a signature. This structure is required to associate the transaction with the chosen key provider, assign a nonce and ensure gas fees for the blockspace are covered.

EIP-8105 follows a two-step execution flow. In the first step, the encrypted transaction envelope is included in a block even though the payload itself remains hidden. Key providers monitor transactions with encrypted payloads, collect the relevant transaction key IDs, and publish either the corresponding decryption keys or a withhold notice once the block builder publishes the data. 

Once the block builder has published the execution payload, the relevant key provider reveals either the decryption key or a withhold notice. A Payload Timeliness Committee (PTC) monitors whether the decryption keys referenced by encrypted transactions are published on time, validates them, and attests to whether a valid key was present or missing. If the key is available and decryption succeeds, the resulting decrypted transaction is executed in the following block. If the key is missing, withheld, or decryption fails, the decrypted payload is skipped, while the envelope remains included, and the transaction fee is still paid.

The EIP also enforces a block structure that prevents MEV-extracting transactions from being inserted in the window between decryption and execution. Decrypted transactions must appear at the beginning of a block, plaintext transactions remain in the middle, and encrypted transactions are placed at the end. This ordering allows encrypted payloads to be revealed and executed only after inclusion, while preventing secondary MEV. 

While EIP-8105 significantly limits MEV exposure, earlier providers in the block retain a limited ability to extract MEV from later transactions by selectively revealing or withholding their decryption keys. The proposal attempts to mitigate this by letting key providers designate other trusted providers and ordering transactions according to the resulting key provider trust graph.

Encrypted Mempools and Ethereum’s Roadmap

Encrypted mempools are becoming an increasingly important part of Ethereum’s roadmap, as the ecosystem looks for protocol-level ways to reduce harmful MEV. While EIP-8105 is no longer being positioned as one of the headliners for the first 2027 hard fork, it remains an open draft, and its ideas continue to inform the broader effort to prepare a leading encrypted-mempool proposal for the upgrade.

US Senator Elizabeth Warren has asked Elon Musk for information on X Money, a payments feature that is expected to be integrated into the X social media platform in the near future.

Warren, who is a longtime critic of Musk and the cryptocurrency industry, wrote in a letter on Tuesday that X Money’s potential stablecoin and crypto integrations could pose risks to the financial system and US national security.

She questioned whether the platform would also issue its own stablecoin, under a legal “carveout” in the Guiding and Establishing National Innovation for US Stablecoins (GENIUS) Act, which allows private companies to issue their own stablecoins. 

Warren said X Money’s limited beta preview suggests it will offer 6% interest on deposits and partner with Cross River Bank, which was subject to enforcement action by the Federal Deposit Insurance Corporation (FDIC), a banking regulator. She said:

“It is unclear what risky investments, intrusive data monetization activities or gimmicks either X Money or Cross River may intend to engage in to pay that yield when the target Federal Funds Rate is 3.5-3.75%.”

Warren’s letter could signal pushback from US lawmakers against private companies issuing stablecoins under the GENIUS stablecoin regulatory framework, which opens the door for the tech sector and non-banks to issue US dollar-pegged tokens.

Related: X rolls out smart cashtags in US, Canada in step toward ‘everything app’

Questions on FDIC insurance for stablecoin deposits

Warren asked whether potential X Money customers were aware that FDIC insurance would not protect them if the platform failed.

In March, FDIC Chair Travis Hill said that stablecoin user deposits are not protected by FDIC insurance under the GENIUS Act.

“The GENIUS Act makes clear that payment stablecoins are not ‘subject to deposit insurance’ or guaranteed by the US government,” Hill said.

However, the legislation did not expressly prohibit stablecoin deposits from receiving pass-through insurance, which extends FDIC insurance to each customer of an eligible financial institution up to $250,000 in the event of a company failure, he added.

Hill said that even though the GENIUS Act lacks a hard prohibition on stablecoin companies extending pass-through FDIC insurance to end users, allowing this would be “inconsistent” with the broader points of the regulatory framework.

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