Quantus Highlights Crypto Market’s Unpreparedness for Quantum Threat

The cryptocurrency industry is unprepared for the transition to post-quantum cryptography.

The cryptocurrency industry is unprepared for the transition to post-quantum cryptography, despite advancements in such computations, according to developers at Quantus.

The project team released a study titled “The State of Quantum: What Crypto Can’t Afford to Ignore,” reviewed by ForkLog. It states that wallets, exchanges, custodians, validators, bridges, and governance systems are at risk.

A significant portion of the market still relies on classical signature schemes—ECDSA and Ed25519. Theoretically, Shor’s algorithm would enable quantum computers to breach such systems once they achieve sufficient power.

In August 2024, NIST finalized the first post-quantum cryptography standards—ML-KEM and ML-DSA. These are positioned as a response to the impending collapse of the classical approach.

Blockchains More Complex Than Traditional IT

Experts at Quantus assert that the crypto market faces stricter constraints than conventional IT infrastructure.

In centralized services, cryptography can be updated via a patch. In blockchains, user fund storage, distributed governance, and public keys can remain on the network for years.

The report mentions a “harvest now, decrypt later” scenario: data is collected today to decrypt later when sufficiently powerful quantum machines become available.

Quantus CEO and CTO Christopher Smith stated that the industry will not have a “clear alarm signal” before the hypothetical Q-Day.

“The crypto market needs to build infrastructure in advance, not under pressure,” he said.

There is currently no timeline for the emergence of quantum computers capable of breaking modern schemes. In May, IBM Quantum’s global sales director Petra Florisun stated that quantum computing is moving beyond laboratory experiments and beginning to be applied to real-world tasks.

Impact on Bitcoin

A separate section of the study is devoted to Bitcoin. Quantus claims that a standard transaction of the first cryptocurrency with ECDSA uses about 97 bytes for the signature and public key. The ML-DSA-87-based variant increases the size to approximately 7187 bytes.

A direct transition to post-quantum signatures without changes to the network architecture, according to the authors, would drastically reduce the number of transactions per block.

The report also mentions BIP-360—a proposal for migrating the Bitcoin blockchain to quantum protection. The document describes the Pay-to-Merkle-Root format as a step to mitigate key exposure risks.

The authors of BIP-360 noted that the proposal does not address all issues. Questions remain about wallet compatibility, block space load, and the fate of old addresses.

Quantus’ Own Solution

The project claims that post-quantum cryptography forms a new version of the “blockchain trilemma”: large signatures impact scalability, and privacy adds additional costs.

Quantus suggests offloading part of the burden outside the main chain through ZK mechanisms. The document mentions Wormhole Addresses, Plonky2, STARK-like proof aggregation, and Poseidon2.

IT Giants Already Moving

The report provides examples of major tech companies transitioning to post-quantum protection:

• Signal with the PQXDH protocol;
• Google with the hybrid X25519Kyber768 in Chrome;
• Apple with the PQ3 system for iMessage.

Quantus concludes that mass consumer services have begun preparing for the post-quantum era ahead of much of the crypto market.

In April, Lightning Labs’ CTO Olaoluwa Osuntokun introduced a prototype tool for protecting Bitcoin wallets from potential quantum attacks.