AmericanFortress Says It Has a Way to Protect Existing Crypto Wallets From Quantum Attacks

Quantum computing has long been viewed as one of crypto's biggest long-term security threats.

If sufficiently powerful quantum computers become a reality, they could potentially break much of the public-key cryptography that secures today's blockchain networks, allowing attackers to derive private keys from exposed public addresses.

One of the most commonly cited examples is the estimated 1.1 million Bitcoin believed to belong to Bitcoin creator Satoshi Nakamoto. Because many of those early wallets have exposed public keys, they are often highlighted as potential targets in a post-quantum future.

Now, privacy infrastructure company AmericanFortress says it has developed a way to protect hierarchical deterministic (HD) wallets—the wallet architecture used by virtually every major crypto wallet today—without requiring users to move funds, migrate addresses, or switch blockchains.

The announcement follows recent industry discussions around quantum risk, including reporting from CoinDesk on the company's research.

A Different Approach to Quantum Security

Most proposed post-quantum upgrades require significant changes to existing wallet infrastructure.

Users may need to generate new addresses, move funds, adopt new cryptographic standards, or rely on blockchain-level upgrades.

AmericanFortress is attempting something different.

The company's newly published research introduces a patent-pending post-quantum signature scheme designed specifically for hierarchical deterministic wallets, which are used throughout the crypto industry to generate wallet addresses from a single master seed phrase.

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Rather than relying on traditional digital signatures alone, the scheme uses zero-knowledge proofs to verify ownership of the original wallet seed at the moment a transaction is signed.

According to the company, this creates an important security advantage.

While a future quantum computer running Shor's algorithm could potentially derive a child private key from a publicly exposed address, it would still be unable to reconstruct the original master seed used to generate the wallet hierarchy.

That distinction forms the foundation of the proposed security model.

No Address Migration Required

One of the most notable aspects of the proposal is its compatibility with existing wallet infrastructure.

AmericanFortress says wallet addresses generated under the scheme remain identical to those produced by standard BIP32-Ed25519 wallet architectures using the same derivation paths.

In practical terms, that means users would not need to migrate funds, register new keys, or move assets to a new blockchain.

The company describes the approach as a potential upgrade path for hundreds of millions of existing wallets rather than a replacement for them.

For an industry that has historically struggled with major wallet migrations and protocol transitions, that compatibility could prove significant if the research gains broader adoption.

How the System Works

The paper introduces what the team calls a "split-proof" architecture. Instead of generating one large proof for every transaction, the process is divided into two separate components.

The first proof verifies wallet derivation from the master seed and only needs to be generated once during wallet initialization or recovery. The second proof is generated when a transaction is signed and remains independent of wallet depth.

The design aims to reduce computational overhead while preserving quantum resistance. Current performance remains a challenge.

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AmericanFortress acknowledges that full proof generation can still take several minutes on consumer hardware due to the complexity of incorporating HMAC-SHA512 operations within a STARK-based proof system.

However, verification times reportedly remain consistent at approximately 18–19 milliseconds regardless of wallet depth, while transaction-specific signing proofs can be generated in under ten seconds.

The team says additional optimizations are already in development.

Beyond Solana

The current implementation focuses on BIP32-Ed25519 wallet architectures, which are commonly used by ecosystems including Solana.

A version designed for Bitcoin's secp256k1 cryptography is already under development and expected to be detailed in a future publication.

According to the researchers, the only wallets that cannot benefit from the proposed approach are those that were created without hierarchical deterministic derivation schemes, including certain early Bitcoin wallets.

That distinction is particularly relevant as concerns around long-term quantum security continue to grow.

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Preparing for a Post-Quantum Future

While practical quantum attacks against blockchain networks remain theoretical today, the industry is increasingly taking the threat seriously.

Governments, financial institutions, and technology companies are investing heavily in post-quantum cryptography as advances in quantum computing continue.

For crypto networks, the challenge is particularly complex.

Any migration away from existing cryptographic systems must balance security, compatibility, performance, and user experience.

AmericanFortress believes zero-knowledge proofs could provide one path forward.

Whether the broader industry adopts the approach remains to be seen, but the publication highlights a growing reality: post-quantum security is no longer a distant research topic.