Is the quantum threat exaggerated? a16z Crypto reveals the real challenges and governance issues of public blockchains

Imagine a scenario where discussions about quantum computing are in full swing, yet mainstream blockchain developers are struggling with a more tangible issue—how to get millions of users to agree and securely upgrade a decentralized network. This is the core contradiction highlighted by a16z Crypto in a report.

According to a16z Crypto’s analysis, the probability of a quantum computer capable of breaking current cryptographic systems appearing before 2030 is extremely low. The more pressing challenge faced by public blockchains like Bitcoin and Ethereum stems from the difficulty of protocol upgrade coordination and governance complexity.

01 The Real Timeline of Quantum Threats

The threat of quantum computing to the cryptography industry is often exaggerated. a16z Crypto explicitly states, “The timeline for the emergence of a quantum computer capable of breaking cryptography (CRQC) is widely overstated, and its appearance before 2030 is highly unlikely.”

The real issue lies in definition. There is a significant gap between what media reports call a “quantum breakthrough” and the actual threat. a16z defines a “cryptographically meaningful quantum computer” as: a fault-tolerant quantum computer capable of running Shor’s algorithm to attack elliptic curve cryptography or RSA.

Currently, all quantum computing platforms—whether ion traps, superconducting qubits, or neutral atom systems—are far from reaching the hundreds of thousands to millions of physical qubits needed to crack RSA-2048 or secp256k1. Simply increasing the number of qubits is not enough; quantum gate fidelity, qubit connectivity, and sustained error correction circuit depth are also critical.

02 The Differential Impact of HNDL Attacks

“Hold Now, Decrypt Later” (HNDL) attacks are a key concept in quantum threat discussions. This attack involves adversaries storing encrypted data now and decrypting it once a cryptographically meaningful quantum computer appears.

Interestingly, the impact of HNDL attacks varies greatly across different cryptosystems. For data requiring long-term confidentiality, such as government communications, the need for quantum-resistant encryption is indeed urgent. But for digital signatures, the situation is entirely different.

Public blockchains like Bitcoin and Ethereum primarily use digital signatures for transaction authorization, not encryption. This means their blockchain data is inherently public, and there is no secret information to be “collected and decrypted.”

03 The Real Challenges for Blockchains: Governance and Upgrade Coordination

While the timeline for quantum threats is exaggerated, the challenges faced by public chains are very real. a16z emphasizes, “Compared to the still-forming quantum risks, the more immediate challenges for mainstream public chains like Bitcoin and Ethereum come from the difficulty of protocol upgrade coordination, governance complexity, and vulnerabilities in layer-1 code.”

Bitcoin faces particularly unique challenges, stemming from the need for extensive social coordination to change the protocol. Even if technically prepared to switch to quantum-resistant signatures, the governance mechanisms of the Bitcoin community could be the biggest obstacle.

The Ethereum Foundation has announced the formation of a new quantum-resistant team, and Coinbase has established an independent advisory committee on quantum computing and blockchain. These initiatives reflect the industry’s recognition of long-term challenges rather than short-term emergency responses.

04 Strategies for Different Cryptographic Primitives

a16z’s analysis reveals that different cryptosystems face varying degrees of quantum threats, which in turn influence their response strategies. This difference is especially pronounced in the blockchain space.

The table below compares several major cryptographic primitives, their quantum risk types, applicability of HNDL attacks, recommended responses, and typical use cases:

05 Industry Response: Prudent Planning and Practical Priorities

Faced with quantum threats and governance challenges, the crypto industry adopts a cautious and pragmatic approach. a16z recommends “planning for quantum resistance ahead of time based on reasonable assessment of the timeline, rather than rushing to execute migrations.”

There are solid reasons behind this cautious stance. Premature migration to quantum-resistant solutions could introduce new risks such as performance degradation, immature engineering, and potential security flaws.

Pantera Capital general partner Franklin Bi points out that compared to traditional financial institutions, blockchain systems may be better suited for the post-quantum era. He believes people “underestimate the unique ability of blockchain to implement system-wide software upgrades globally.”

06 Current Market and Investment Considerations

As of January 26, 2026, Bitcoin is priced at $87,739.80, and Ethereum at $2,864.71. The prices of these mainstream public chains reflect market confidence in their long-term value.

For crypto traders, understanding the true timeline of quantum threats helps inform smarter investment decisions. In the short term, traditional security issues like code vulnerabilities, side-channel attacks, and fault injections are more pressing than quantum computing.

At Gate Exchange, investors can focus on projects that innovate in protocol governance and upgrade mechanisms, which may better address future technological challenges.

Future Outlook

When will quantum computers truly threaten the cryptographic world? The answer is: much later than most people imagine. The real test for public chains like Bitcoin and Ethereum lies in how they coordinate global participants to complete protocol upgrades and address real-world governance deadlocks.

As the industry shifts focus from distant quantum threats to immediate governance challenges, it may discover that the most fragile part of blockchain technology is not the cryptographic algorithms, but humans’ ability to coordinate and reach consensus.