Quantum risk begins to diverge, revealing a disconnect in the exposure pathways of Bitcoin and Ethereum

Authored by: Fang Dao

Over the past few days, some readers have asked me a more specific question:

If quantum computing really enters the executable stage, will different public chains be impacted at the same time?

From a theoretical standpoint, the answer is “yes.”

But from a structural standpoint, the answer is closer to “no.”

Once quantum computing enters the engineering track, the market starts to reassess a more granular question: how will the potential impact of this underlying cryptography be distributed across public chains with different architectures?

At first glance, systems based on Elliptic Curve Digital Signature Algorithm (ECDSA) face similar risks; but in real structural terms, the way risks become exposed is significantly asymmetric.

The first major fault line in risk comes from the exposure path between addresses and signatures.

In Bitcoin’s (P2PKH) model, as long as funds have not been spent, the chain only publicly reveals the address hash rather than the public key—this creates a natural “delayed exposure” mechanism for potential attacks.

By contrast, Ethereum’s account-based model and high-frequency contract interactions keep the public keys of a large number of active accounts exposed for the long term.

Under the same technical premise, the immediate exposure attack surface differs across networks. This difference means the risk is no longer evenly distributed, but instead exhibits path dependency.

The second layer of difference comes from the system’s upgrade mechanism.

Bitcoin’s consensus formation is highly restrained; any change involving underlying cryptographic algorithms comes with a longer cycle and higher coordination costs. Ethereum, on the other hand, has a higher iteration frequency and more flexible protocol adjustment capabilities.

This leads to a not-so-intuitive result:

Systems with broader exposure paths may have faster migration capabilities; while more conservative systems may find their defense cadence constrained by consensus “stickiness.”

Risk exposure and response speed do not correspond linearly.

The third difference comes from the ecosystem structure.

Bitcoin’s functionality is concentrated on value storage, so its risk boundaries are relatively clear. Ethereum, meanwhile, supports a large number of smart contracts, Layer2, and decentralized finance (DeFi) structures.

When the underlying signature mechanism is impacted, its effects no longer remain limited to the assets themselves; instead, it may trigger a chain reaction through the application layer. The higher the system complexity, the longer the potential propagation paths of the impact.

Under this kind of structure, quantum risk is no longer a single, uniform variable—it begins to show layered characteristics. It no longer simply manifests as “whether it is secure,” but depends on: which paths are exposed first, and whether the system can complete migration within the window of opportunity.

At the current stage, quantum computing has not yet formed realistic attack capability. But as technical paths become clearer step by step, discussions of risk have shifted from “whether it will happen” to “how it will be distributed.”

Under this framework, the market ultimately will not only price “whether it is secure,” but will start pricing: which category of assets is more likely to be exposed first when the shock arrives. Under the same technical singularity, different public chains are very unlikely to perform synchronously.

References

Ethereum Research, Bitcoin Core Discussions, NIST PQC

Disclaimer: This article is for information and research exchange only and does not constitute any investment advice.