Why Are People Scared That Quantum Will Kill Crypto?

Original Title: Quantum Isn't a Threat to Web3. It's an Upgrade.
Original Author: DAVID ATTERMANN
Translation: Peggy, BlockBeats

Editor's Note: The discussion surrounding "Will Quantum Destroy Web3" often overlooks the true direction of change. This article points out that quantum is not a threat but a migration of security infrastructure: robust cryptography, tamper-evident communication, physical randomness, and identity proofs are gradually sinking to the foundational capabilities. In this process, blockchain no longer needs to repetitively "compensate" for an untrusted network environment at the software layer but can focus more on irreducible issues such as governance, incentives, and cross-domain collaboration.

More importantly, the advent of quantum coincides with the realization of autonomous AI systems, where security becomes infrastructure, enabling Web3 to truly enter a mature stage of serving "autonomy, commitment, and coordination."

The following is the original text:

The mainstream debate surrounding "Will quantum computing kill Web3" actually misses the point. Such framing is inherently inverted. Quantum computing will not make digital systems less secure; instead, it will further embed security into the lower layers of infrastructure. As new cryptographic standards take root and novel secure communication methods become feasible, fundamental security capabilities will become more cost-effective and standardized across the entire internet.

Simultaneously, AI systems are transitioning from "thinking" to "acting." When intelligent assistants can do more than just answer questions but can book flights, transfer funds, and manage resources, the real challenge shifts. It is no longer a question of whether AI can generate good answers, but whether software can securely take action across disparate systems and organizations that do not trust each other. Proving what AI has done, where the data came from, and what it is allowed to do is becoming the most crucial constraint.

This is precisely the same fracture line that prevents all current JARVIS-like visions from materializing. The true bottleneck lies not in intelligence but in trust. An assistant that still requires human approval when spending money, accessing sensitive data, or allocating resources cannot truly be autonomous. Once real authorization is involved, if there is no machine-verifiable, shared way to prove identity, permissions, and compliance, the so-called "autonomy" immediately fails.

Quantum computing, at this moment when trust and collaboration issues become unavoidable, reduces the cost of security.

1. How Quantum Actually Changed Things (and What It Didn't)

When people talk about "quantum," they are usually referring to quantum computers. These are not "faster GPUs," but a class of specialized machines that leverage quantum mechanical properties to far outperform classical computers on certain specific problems.

What they excel at includes: factoring large numbers, solving discrete logarithm problems, certain specific optimization and simulation problems.

What they do not excel at includes: general computing, running large software systems, replacing cloud computing infrastructure, training AI models.

So, what exactly will quantum computing break?

The answer is: a part of today's public-key cryptography. RSA and Elliptic Curve Cryptography (ECC) are built on the type of mathematical problems that quantum computers are best at solving. This is crucial because cryptography is not only a fundamental primitive of blockchain, it is the trust foundation of the entire Internet—login mechanisms, digital certificates, signatures, key exchanges, identity systems, are all reliant on it.

The real uncertainty lies in the timeline, not the direction. Most credible estimates suggest that a quantum computer with "cryptographically significant" capabilities is still 10–20 years away, but no one can completely rule out faster progress or some kind of "leap" breakthrough.

Most Immediate Near-Term Risk: Harvest Now, Decrypt Later (HNDL)

The most quantum-related immediate risk is not a sudden collapse of the global security system one day, but what's known as HNDL (Harvest Now, Decrypt Later).

Attackers could very well mass collect encrypted communications and data today, only to decrypt this historical data when future quantum computing capabilities mature.

This pattern would pose long-term exposure risks to: government and defense communications, corporate intellectual property and trade secrets, medical data and personal privacy records, legal and financial archives.

It is for this reason that Post-Quantum Cryptography is being taken seriously right now by national governments, cloud service providers, and regulated industries. Data transmitted today often needs to remain confidential for decades; once you assume that the "future will definitely be decryptable," then the existing security guarantees are actually invalidated.

This Is a Security Migration, Not a Systemic Collapse

Post-Quantum Cryptography does not require quantum hardware. It is essentially a software and protocol-level upgrade that covers TLS, VPN, wallets, identity systems, and signature schemes. This will not happen on a single "switch-over day," but rather will be a slow, uneven infrastructure migration process, similar to IPv6 — unavoidable but gradual.

This change will have a much greater impact on enterprise and national-level infrastructure than on the blockchain itself. Blockchain is inherently a public system, where the core secret that truly needs protection is the private key, not the historical transaction data. For Web3, quantum computing brings not a survival crisis, but a cryptographic upgrade path issue, rather than a total system overhaul.

This shift has already emerged in the mainstream ecosystem. The Ethereum Foundation recently elevated post-quantum security to a core protocol-level priority, initiating specialized research and test environments around post-quantum signatures, the account model, and transaction mechanisms. This signifies that risk awareness has shifted from a "someday in the future issue" to an "ongoing infrastructure migration," even though true large-scale quantum hardware has not yet appeared.

II. The Most Easily Overlooked Change: Alteration at the Network Layer

If quantum computing is concerned with the mathematical foundation for securing keys, then quantum communication is concerned with the trust model of the network itself.

Quantum communication does not mean "transmitting application data through a quantum computer." Although it has multiple implementation forms (which will be explored later), in reality, the most core application is Quantum Key Distribution (QKD): using quantum states to establish a tamper-evident communication channel. The message itself remains classical data, still encrypted; what truly changes is that any silent eavesdropping will be detected at the physical layer.

This is not a faster network but a network trust mechanism that cannot be subversively infiltrated.

Some quantum properties are uncopyable and cannot be observed without causing disturbance. When these properties are used to generate encryption keys or validate communication channels, interception is no longer "silent." Once someone attempts eavesdropping, the observation itself leaves detectable traces.

Why This Will Change System Design

The reason this is important is that a significant portion of Web3's current defense architecture is based on one premise: the network channel is adversarial and invisible.

Traffic can be quietly intercepted; man-in-the-middle attacks are hard to detect; network-layer trust is extremely weak.

Therefore, the upper-layer systems have to "overcompensate" through replication, validation mechanisms, and an economically secure design.

If the infrastructure layer itself embeds protections for channel integrity, quantum communication actually serves to lower the cost of maintaining channel security. This point is often overlooked in the mainstream narrative of the "quantum apocalypse."

Will It Really Scale?

Similar to quantum computing, the widespread adoption of Quantum Key Distribution (QKD) is likely still 10–20 years away. However, the possibility of a sudden timeline compression cannot be ruled out — for example, with breakthroughs in quantum relays, satellite networks, or integrated photonics technology.

III. The Trust Issue of Autonomous Systems

Quantum is driving a security migration across the Internet. Over time, strong cryptosystems and tamper-evident communication channels will become part of the infrastructure, no longer a differentiating capability.

However, what truly makes "collaboration" a core bottleneck is the rise of autonomous AI agents.

Autonomous systems cannot rely on informal trust like humans or institutional shortcuts. By default, they require:

Verifiable execution: Agents cannot be trusted based solely on their claims; there must be proof.

Coordination mechanisms: Multi-agent workflows need a neutral shared state carrier.

Data provenance: Source verification is crucial when synthetic and adversarial data proliferate.

Commitment mechanisms: Agents must be able to make enforceable commitments that other agents can rely on.

While the quantum network cannot directly solve coordination issues, it will commoditize security capabilities at the base layer. As security becomes part of the infrastructure, more coordination can happen off-chain with stronger guarantees. Identity and membership relations will be closer to the underlying network structure. For certain types of workflows, global broadcast replication is no longer necessary. Blockchain is transitioning from a "pure broadcast system" to the coordination backbone of autonomous systems.

IV. Frontier Quantum Primitives

The following content pertains to longer-term possibilities, assuming the quantum network can move beyond niche applications and achieve scalability. Once implemented, they will strengthen underlying security assurances and open up new protocol design space. Similar to QKD, the significance of these primitives is to unlock resources for the "coordination bottleneck."

Some are closer to real-world production environments, while others signal architectural directions for the evolution of future trust mechanisms.

First Layer (0–10 Years)

Physical Unclonable Randomness: Random number generation directly constrained by physical processes, hard to predict or manipulate.

Unclonable Identity with Proof Mechanism: Identity and authentication based on physical characteristics to prevent duplication and forgery.

Second Layer (10+ Years)

Time Synchronization as a First-Class Primitive: Time is no longer just a system parameter but a verifiable foundational capability.

Verifiable State Transfer: Cross-system state changes can be directly proven by underlying mechanisms.

Third Layer (Cutting Edge Research, High Uncertainty)

Entanglement-Based Coordination Primitive: Establishing new coordination structures using quantum entanglement.

Fully Trust-Minimized Cross-Domain Communication Mechanism: Achieving nearly trust-free message passing between different trust domains.

Overall, quantum is not a force that "breaks Web3" but a force that drives the upgrade of security infrastructure. And as security costs decrease, the real bottleneck will no longer be cryptography but how to make autonomous systems reliably collaborate in an untrusted environment.

1. Verifiable State Transfer

From "Software-Enforced Scarcity" to "Physical Unclonability"

In today's blockchain systems, unreplicable ownership is achieved through network-wide consensus. Scarcity is a rule set by the protocol and maintained through replication and consistency among a large number of nodes. The existence of a ledger is largely to ensure that the same state is not replicated or double-spent.

Quantum teleportation introduces a completely different primitive: states can be transferred but cannot be replicated during the transfer and are "consumed" at the moment of transfer. In other words, unclonability no longer relies entirely on software and protocol constraints but becomes a property of the physical underlying layer itself.

Why is this important? How will it change system design?

Hardware-Backed Custodianship: Regulated anonymous instruments, sovereign-grade credentials, or real-world tangible assets, whose control can be bound to unclonable, hardware-proof-capable states.

Asset Anchoring with Lower Trust Assumptions: A mechanism for partially bridging real-world assets that can rely on the physical irreproducibility, without needing to fully depend on committees, multisigs, or pure social trust.

Protocol Simplification: Part of the scarcity guarantee is moved to a lower layer of the stack, reducing the complex logic in the protocol used solely for "anti-duplication."

2. Entanglement as a Trust Primitive

Blockchains coordinate through global replicated state and consensus to resolve conflicts. Cross-chain interactions often rely on heavy validation processes or trusted relays; finality is usually post-hoc, determined by blocks and confirmation.

Quantum entanglement introduces another primitive: achieving shared correlation without a central coordinator. It allows participants to establish consistency or alignment properties at an earlier stage without exposing the underlying data itself.

From this perspective, entanglement is not about "faster consensus" but a mechanism to establish trust constraints at the frontend of the pipeline, opening new design spaces for future cross-system, cross-domain coordination.

Why It's Important and How It Will Change System Design:

Earlier synchronization: Sequencers can establish a consistent view of "ordering commitments" before final settlement.

Cleaner cross-domain alignment: Multiple domains can prove they observed the same event stream without relying on a single relayer.

Reduced overhead in upper-layer reconciliation: Some "alignments" can be established before the need for heavy global adjudication, reducing the additional hardening costs high-level protocols make for adversarial networks.

4. Physically Enforced Randomness

From a gameable randomness beacon to unpredictability endorsed by physics. Randomness underpins validator selection, block producer election, committee sampling, auctions, and various incentive mechanisms. Today's randomness is mostly constructed at the protocol layer, leaving room for manipulation and bias at the edges.

Quantum processes can generate randomness that is unpredictable and unbiased under physical assumptions.

Why It's Important and How It Will Change System Design:

Cleaner committee and proposer selection: Reducing the attack surface for subtle manipulation strategies.

Fairer Sorting and Auctions: Mitigating MEV Extraction with a system less sensitive to transaction ordering.

More Robust Mechanism Design: Incentive mechanisms are harder to game at the "randomness layer."

4. Unclonable Identity and Attestation

From "key equals identity" to "device equals identity." Identity in Web3 today is nearly synonymous with "holding a key." Sybil resistance relies mainly on economic costs or social heuristic rules. Node identities are also mostly loosely anchored at the software layer.

Quantum states are unclonable. When combined with hardware attestation, it becomes possible to achieve unclonable device identity and stronger remote attestation: proving that a message or computation indeed came from a specific physical endpoint.

Why This Is Important and How It Will Change System Design:

Stronger Endpoint Assurance: Messages and execution claims can be bound to a specific physical environment.

Reduced Trust Surface of Relayers and Oracles: Proving ability is closer to hardware rather than relying solely on software identity and claims.

More Reliable Verifiable Computation: Execution traceability becomes harder to forge.

5. Elevating Time Sync to a First-Class Primitive

From "soft clocks" to "protocol-level time." The way blockchain handles time is fundamentally a soft assumption. Slot timing and ordering can be exploited, and even tiny latency advantages can drive MEV. Quantum-secure clock synchronization enables tighter time coordination across long distances.

Why This Is Important and How It Will Change System Design:

Fairer Block Production Windows: Reducing latency asymmetry to limit certain frontrunning strategies.

Cleaner Cross-Chain Settlements: Tighter timeframes reduce race conditions.

More Stable Ordering: Protocol timing becomes less sensitive to network jitter.

6. Minimal Trust Cross-Domain Coordination

From "committees everywhere" to "physically endorsed message passing." Cross-chain security remains one of Web3's biggest operational risks. Bridges rely on committees, multisigs, relayers, and oracles—each adding to the trust surface and potential failure modes.

As both entanglement and tamper-evident channels mature, different domains can increasingly prove they have observed the same set of commitments or event flows with fewer social trust assumptions.

Why this is important and how it will change system design:

Smaller trust set for bridges: With validation closer to the underlying, catastrophic failure modes diminish.

Cleaner cross-domain ordering: No need to rely on centralized operators, making it easier to establish shared ordering.

Security down the stack migration

Today's blockchains simulate scarcity, randomness, identity, ordering, and cross-domain messaging at the software layer because the underlying network and hardware are not inherently trusted. Quantum networks push some aspects of capabilities like authenticity, unclonability, tamper detection, randomness, and synchrony into the infrastructure fabric.

This mirrors past infrastructure evolutions: TLS brought cryptography to the network layer; TEEs brought trust to hardware; secure boot brought boot integrity to the firmware layer.

Blockchain will not become obsolete; it will be "unburdened" from reimplementing every trust primitive in software and will focus more on those problems that cannot be eliminated: governance, incentives, collusion, and adversarial shared state.

Five, Counterarguments, and Real-World Constraints

Even if quantum-secure networks are limited to a few strategic corridors, this alone is enough to reshape the standards and design assumptions across an entire tech stack. Highly trusted communication doesn't have to be "ubiquitous" to affect system construction: as long as a part of the network defaults to providing a tamper-evident channel, the threat model will shift upstream, and fundamental security assumptions will also begin to change more broadly.

In reality, quantum-secure communication remains expensive, fragile, and limited in coverage. Hardware deployment and operation are challenging and seamless integration with existing Internet infrastructure is difficult. For many use cases, relying solely on post-quantum cryptography may already be sufficient, so quantum-safe links are more likely to focus on high-value environments: government networks, financial infrastructure, and critical national systems.

Ultimately, a hybrid trust landscape will emerge: some corridors will have stronger default assurances, while the open Internet remains adversarial.

This uneven deployment will not weaken the architectural shift but will present it in a "skewed" form.

Six, How Systems Will Adapt Over Time

Large infrastructure transitions are rarely "one-and-done." Changes in system design often precede widespread adoption of new technology, especially in the security realm. Once new standards are adopted, early deployments occur, builders will begin to assume a new baseline, even as the deployment of infrastructure remains uneven.

A more realistic evolution path is roughly as follows:

Future 5 Years: Security Capability Commercialization

Post-quantum cryptography will gradually unfold in cloud service providers, enterprises, and regulated industries. "Quantum security" will become part of the default security checklist, no longer a unique selling point. Early quantum-safe network links will appear in high-value scenarios such as finance, government, and critical infrastructure.

Even though these upgrades are not yet widespread, they will begin to shape how systems are built: teams will assume a stronger baseline for the network and the cryptographic layer, shifting more attention to how systems interact, coordinate actions, and enforce rules among untrusted parties.

5–10 Years: Design Assumptions Migration

Once stronger security primitives become the norm, systems will no longer need to be heavily over-engineered for adversarial networks and weak cryptography. The underlying platforms will start integrating integrity, hardware proof, and verification tools — components that were once seen as "advanced features."

At this stage, the changes occur more in "how people think about system design" rather than the infrastructure itself. Builders will begin designing systems for a world where "default security holds," and the real complexity shifts to how systems interact, how permissions are executed, and how cross-border behavior is coordinated.

10+ Years: Infrastructure Catches Up with Design Paradigms

Quantum-safe channels and tamper-evident communication will become more common in major financial hubs, government networks, and critical corridors. By then, most modern systems have been designed under a stronger security assumption, and the infrastructure finally catches up to design patterns that appeared years ago.

Quantum: Driving Autonomy's Next Stage

Viewing quantum as the primary narrative of the Web3 threat is actually the opposite. Quantum is more like an accelerator: it arrives at the same time autonomous AI systems are beginning to enter the real world.

It pushes security primitives into the infrastructure layer. Strong cryptography, tamper-evident channels, and verifiable integrity become cheaper, more standardized, and no longer a differentiating advantage. This reduces the underlying "trust cost," unleashing new design space to build the primitives that AI agents truly need to wield real power: verifiable execution, enforceable permission boundaries, and bindable commitments between systems that do not share trust.

Quantum will not kill Web3; it will force Web3 to mature.

When security becomes infrastructure, what remains are the real challenges — also the initial issues Web3 set out to solve: establishing autonomy, commitment, and coordination in inherently untrusted systems.

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