Regulated crypto bank Anchorage Digital has presented a strategy to prepare institutional assets for the post-quantum era. The organization also announced the implementation of hybrid protection for internal TLS connections.
For cryptocurrencies, the key risk is not related to mining or hashing, but to digital signatures: Shor's algorithm theoretically allows the computation of a private key from a revealed public one.
"Quantum computing is not a moment, but a migration. At Anchorage Digital, we have been building infrastructure for this migration from day one," said Nathan McCauley, co-founder and CEO of the crypto bank.
According to Anchorage, client bitcoins are in a more secure position due to the use of addresses based on a hash of the public key. Such a scheme does not reveal it until a transaction is sent, and the company itself follows the practice of minimizing address reuse.
Regarding TLS connections, the organization stated that managed employee devices on ChromeOS already use post-quantum key encapsulation—a secret key agreement mechanism resistant to future quantum attacks.
Another element of the strategy is hardware security modules where cryptographic keys are stored and processed. Anchorage stated that it is deploying post-quantum cryptography in its production infrastructure and testing the performance of different algorithms.
What are quantum computing and quantum computers?
In addition to internal measures, Anchorage proposed a Post-Quantum Turnstile mechanism for migrating old accounts to post-quantum keys. It uses STARK—a type of zero-knowledge proof that allows confirmation of secret knowledge without revealing it and does not require a trusted setup.
The idea addresses one of the problems of Bitcoin's future migration. If the network ever disables classical signatures, some funds in addresses with unrevealed public keys will remain protected from quantum attack but may become inaccessible to their owners. Turnstile proposes transferring the signing right to a post-quantum key without revealing the old private or public key.
According to Anchorage's estimate, this approach could be applicable to approximately two-thirds of the circulating coins.
The crypto bank has also open-sourced sqisign-rs—an implementation of the SQIsign digital signature scheme in Rust. Representatives of the organization claim that SQIsign yields a signature size approximately seven times smaller compared to Falcon.
Earlier, Glassnode analysts estimated that around 6 million BTC in addresses with revealed public keys could be at risk from quantum attacks.
Recall that in May, Quantus developers pointed out the cryptocurrency market's lack of readiness for the transition to post-quantum cryptography.
