Company AmericanFortress published a preprint on ZKPoSP — a cryptographic scheme for protecting hierarchical deterministic wallets from potential quantum attacks without changing addresses.
According to the authors' design, ZKPoSP allows preserving the existing address format while replacing the classical signature with a non-interactive zero-knowledge proof (NIZK).
AmericanFortress also described the QBIP32 scheme. It is designed to generate a signature scalar, a separate quantum-resistant witness, and a chain code within a single function call. The authors claim that QBIP32 can be applied to different elliptic curves of prime order, including secp256k1 and Ed25519.
In the preprint, the post-quantum security of the scheme is described as assumed. According to the document, it relies on the resilience of hash functions and NIZK proofs against quantum adversaries. However, for the scheme to work in a specific network, nodes must support verifying such proofs instead of standard signatures. Neither Bitcoin, Ethereum, nor Solana currently do this.
AmericanFortress implemented the constructions in Rust using RISC Zero. According to the authors, creating a signature proof takes about 12–13 seconds, while verification takes about 9–10 ms.
Quantum & After. Question No.2: How are blockchains preparing for the "quantum" era?
In a March report, Galaxy company indicated that Project Eleven estimates approximately 7 million $BTC, or about $470 billion at prices at that time, as potentially vulnerable. This referred to addresses whose public keys have already been disclosed on-chain.
On July 28, Freedom Factory introduced the PQ1 hardware wallet for Ethereum and EVM-compatible networks. In a press release, the company stated the use of SPHINCS+C10 and ERC-4337 smart accounts.
On July 23, Anchorage Digital, ARK Invest, BlackRock, Block, Blockstream, Coinbase, Fidelity Digital Assets, Galaxy, and Strategy announced the launch of the Bitcoin Security Consortium. Participants promised to collectively allocate $15 million over three years to developers and researchers working on the long-term security of Bitcoin, including post-quantum cryptography.
On July 21, Galaxy launched a nearly identical program to prepare the first cryptocurrency for potential threats from quantum computers. Up to $5 million will be directed in grants to developers and researchers.
Earlier, the Stellar Development Foundation presented its document, and the Algorand Foundation also published a roadmap. Nicolas B. Consigny, lead of the Kohaku project at the Ethereum Foundation, proposed a solution called SPHINCS-, which would allow securing wallets without conducting a hard fork.
Recall that in May, AmericanFortress presented a post-quantum signature scheme to protect existing crypto assets, including "dormant" wallets from the Satoshi era with 1.1 million $BTC. The new publication differs by focusing on hierarchical deterministic wallets and describing ZKPoSP/QBIP32 as a general mechanism for different curves and networks.
Will Quantum Hackers Steal Satoshi Nakamoto's Billions?
