Preparing Blockchain Security for the Quantum Transition       

By Riyaz Faizullabhoy, Engineering Lead, Security Engineering at Anchorage Digital; BSSC Board Member

Quantum computing is not yet capable of breaking the cryptography that protects most blockchain systems today. That does not mean blockchain organizations can afford to wait.

There is useful work that can happen now: understanding where your systems are exposed, strengthening infrastructure that can already be upgraded, testing what a future cryptographic change could mean for your systems, and talking to the providers and blockchain networks you depend on.

For security teams, this is less about predicting exactly when the threat will arrive and more about being ready when the industry needs to act.

Understand your exposure

The primary concern for most blockchains is elliptic curve digital signature algorithms, such as ECDSA, EdDSA, and BLS.

Bitcoin, Ethereum and other major networks use these cryptographic signatures to establish ownership and authorize transactions. A sufficiently capable quantum computer could undermine some of the mathematical assumptions behind these signatures, potentially allowing an attacker to derive a private key from a public key and take control of assets.

That creates both an individual and systemic risk. An attack could target specific accounts, but attacks against significant addresses or widely used blockchain infrastructure could also result in fear, uncertainty and doubt towards an entire network.

Other cryptographic systems deserve attention, too. While hashing, which is used in areas such as mining and address creation, remains comparatively resilient to quantum attacks, public key encryption is a more relevant concern in systems that store sensitive information. An attacker could collect encrypted data today and attempt to decrypt it later when sufficiently capable quantum computing becomes available — the proverbial “harvest now, decrypt later” risk.

The first step, then, is to understand your own cryptographic footprint. Ask:

• Where are digital signatures used?
• What client or operational information is encrypted?
• Which systems rely on transport layer security (TLS) for network communication?
• Which assets or addresses could have their public keys exposed?
• Which parts of your infrastructure depend on external providers?
• What would happen if a blockchain you support changed its signature algorithm?

The answers will vary between organizations and blockchains. For example, Bitcoin’s different address and transaction patterns affect whether public keys are exposed. Organizations can analyze their holdings to understand which assets could be more exposed under a future quantum threat and consider appropriate preventative measures.

There is no known feasible quantum attack against these systems today. The point is to understand what you would need to do if that changes.

Secure what you can change today

Not every part of the quantum transition depends on a blockchain protocol upgrade.

Organizations can already examine the cryptography protecting the infrastructure around their blockchain systems. Quantum-resistant options for TLS, for example, are already supported by many browsers and cloud providers. Teams should determine whether their infrastructure can support them and what would be required to deploy them.

The same assessment should extend to other systems that sit around the blockchain, including:

• Wallet and custodian infrastructure
• Cloud infrastructure
• Databases and other encrypted data
• Internal applications and services
• Network communications
• Third-party integrations

This is also where crypto agility — the ability to change cryptographic algorithms without redesigning an entire system — becomes important.

For blockchain operators, that means asking a practical question: If a blockchain we depend on announced a migration to a new quantum-resistant signature algorithm, how quickly could our systems support it?

The answer may depend partly on systems and providers outside your organization. If you use a wallet provider, custodian, staking provider or other infrastructure partner, understand how they are approaching crypto agility and what their migration process would look like.

Plan for the changes you don’t control

Preparing a blockchain ecosystem for a cryptographic change is different from upgrading a conventional IT environment because blockchain networks are decentralized.

Decisions about code, protocol changes and validator software involve multiple organizations and individuals. Even when the technical solution is clear, coordinating its adoption can take time.

That means organizations need to prepare beyond their own infrastructure:

1. Track the networks you depend on. Understand where each network stands on post-quantum cryptography and what changes are being considered.
2. Talk to critical technology providers. Ask wallet, custody, staking and infrastructure providers how they plan to support future cryptographic changes.
3. Map your dependencies. Know which parts of a migration you control and which require action from another organization.

The goal is to avoid discovering a critical dependency when the migration window has already opened.

For organizations closer to the blockchain protocol, preparation should also include benchmarking. Quantum-resistant signature algorithms can have different sizes and other properties from the algorithms currently in use. Those differences could affect performance, storage and other parts of the system.

Developers and infrastructure teams should start testing questions such as:

• How would a new signature algorithm affect performance, storage and transaction processing?
• Which components would need to change?
• Where could the new cryptography create bottlenecks?

Starting that work now gives teams more time to understand the implications before a specific migration path is finalized.

Prepare, don’t panic

There is already a lot of uncertainty around when practical quantum attacks will become possible and how individual blockchain networks will respond.

That uncertainty is not a reason to wait.

You can take some comfort from the fact that the industry is already working on the problem across multiple levels — from blockchain foundations and protocol developers to infrastructure providers and applications. Standards organizations such as National Institute of Standards and Technology (NIST) are helping establish recommendations for quantum-resistant algorithms. The National Security Agency (NSA) recently released their Post-Quantum Cryptographic Research Hub. Blockchain Security Standards Council’s (BSSC) updated Node Operation Standard, Smart Contract Security Standard, and General Security and Privacy Guidelines contain guidance on protecting systems against future quantum computing threats, with more to come.

For individual organizations, the practical message is simple: understand your current exposure, make the changes that are available today, build crypto agility into your systems, and start conversations with the people you will depend on for the rest.

We are in a preparation window. There is important work to do, but there is also time to do it thoughtfully. Use the time to understand your systems and dependencies so that when the technology and the networks are ready for the next step, your organization will be ready too.

About Anchorage Digital

Anchorage Digital is the proven infrastructure layer for modern financial markets that gives institutions a single platform to participate in digital assets, including prime services, tokenization, stablecoins, and the governance framework for agentic finance. Home to Anchorage Digital Bank N.A., America’s first federally regulated digital asset bank, Anchorage Digital also serves institutions through Anchorage Digital Singapore, licensed by the Monetary Authority of Singapore; Anchorage Digital NY, which holds a BitLicense from the New York Department of Financial Services; and self-custody wallet Porto by Anchorage Digital. Anchorage Digital Bank also offers fiat custody services through an FDIC-insured, licensed sub-custodian. Anchorage Digital is funded by leading institutions including Andreessen Horowitz, GIC, Goldman Sachs, KKR, and Visa, with a valuation of $4.2 billion. Founded in 2017 in San Francisco, California, Anchorage Digital has offices in New York, New York; Porto, Portugal; Singapore; and Sioux Falls, South Dakota. Learn more at anchorage.com, X, YouTube, and LinkedIn.

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