Researchers at AmericanFortress have unveiled a patent-pending post-quantum signature scheme aimed at fortifying the global cryptocurrency ecosystem against potential future quantum threats, while also eliminating the need for significant fund migrations. This innovative solution promises to safeguard even the substantial 1.1 million Bitcoin (BTC) stash associated with Bitcoin’s enigmatic creator, Satoshi Nakamoto. Alongside this, nearly 5 million BTC held in inactive accounts, amounting to a staggering combined value of approximately $400 billion, could also be protected.
In an interview, Michal Pospieszalski, the CEO of AmericanFortress, emphasized that dormant wallets are not helpless against malicious hackers who might attempt to seize these assets and flood the market, leading to catastrophic results. He clarified that a primary area of misunderstanding pertains to the older Bitcoin wallets, which are classified as “Pre-BIP32” addresses. These wallets lack seed phrase derivation and cannot be upgraded automatically, a feature available to newer wallets. To mitigate this vulnerability, the AmericanFortress protocol proposes a defensive freeze through a backward-compatible soft fork.
“Our quantum-resistant protocol would automatically freeze and protect those funds until governance decides what to do with them after Q-day,” Pospieszalski explained. He highlighted that decisions regarding the frozen assets would ultimately require community consensus, including options to move, burn, or redistribute these funds. Importantly, he noted that this enhancement means even Satoshi’s wallets can be secured through a minor Bitcoin Improvement Proposal (BIP) currently under development.
The implications of this protocol extend beyond Bitcoin, offering protection to major blockchain networks such as Ethereum, Solana, and Tron. This announcement comes on the heels of an $8 million seed funding round led by SAVA Digital Asset Fund, Moon Pursuit Capital, and 0G Labs. Concurrent with the funding efforts, AmericanFortress also released a cryptographic paper pinpointing the specific network performance issues that have hampered previous post-quantum trials.
In recent testing, a standard quantum-security evaluation on the Binance Smart Chain was successful; however, it resulted in a 40% reduction in transaction throughput. Unlike traditional methodologies that necessitate the creation of entirely new blockchains or complex address rotations, AmericanFortress adopts an innovative approach utilizing zero-knowledge (ZK) proofs to validate master seed ownership at the transaction point. This strategy incorporates three distinct solutions: Pre-BIP32 raw key protection, standard BIP32 quantum protection, and a high-speed “QBIP32” derivation scheme, all without compromising performance by integrating natively with existing cryptographic curves.
“It’s just a node and wallet software update in that order,” Pospieszalski noted, indicating the simplicity and efficiency of the implementation. The risks posed to cryptocurrency systems are significant, he asserted, explaining that while quantum computers cannot decipher master seed phrases, they can reverse engineer private keys from exposed on-chain wallet addresses, a vulnerability affecting over $600 billion in crypto assets, including all Solana addresses.
For users actively engaging with their wallets, upgrading to a quantum-proof status only requires about 50 milliseconds via a straightforward wallet prompt. For dormant wallets derived from seeds, protection can be programmatically executed at the base layer. Pospieszalski emphasized that the cost associated with this quantum-proofing process is remarkably low, akin to the expense of a single rollup transaction rather than necessitating payment for each historical transaction.
AmericanFortress is actively pursuing licensing its software development kit (SDK) to Layer 1 and Layer 2 blockchains for marketing advantages, while remaining open to potential exclusive acquisition offers. The firm anticipates that its cryptographic methods for Bitcoin will be ready for discussion soon, with a formal presentation planned for June 2 in Paris.
Pospieszalski expressed optimism about the future, seeing this development as a pivotal moment for the sustainability of digital assets. “Sudden quantum proofing of BTC is now possible,” he asserted, highlighting the transformative potential of this technology in the evolving cryptocurrency landscape.


