Olaoluwa Osuntokun, CTO of Lightning Labs, published a proof of concept on the Bitcoin developer mailing list on April 8th that is one of the open questions in the post-quantum debate. soft fork An emergency that disables the most common spending mechanism in Taproot addresses.
he soft fork The possibility that developers are discussing is triggered as an emergency response to the arrival of “Q-Day”, “Key usage pass” This is a mechanism that allows funds to be used in a simple Schnorr signature to ensure that a quantum computer cannot derive the private key from the taproot address’s public key.
This will cause wallets that use this scheme (mostly those generated with the BIP-86 standard) to be blocked indefinitely. No alternative spending routes have been established.
However, Taproot is addressed with a separate spending route. “Script path”they keep working.
The solution proposed by Osuntokun is the use of zk-STARK technology, a type of zero-knowledge proof (ZK proof) This allows users to prove that they are the rightful owner of the address. without revealing your private key or master seed. This system allows users to access and move their funds into a secure post-quantum format. key usage path Disabled.
Another tool in the post-quantum kit
A zk-STARK proof is a cryptographic mechanism that allows you to prove that something is true without revealing the information that proves it. In this case, Bitcoin users would prove that they know the seed that generated a particular public key without disclosing it.
The advantage of the post-quantum scenario is that the zk-STARK test relies on symmetric encryption. It is believed to be resistant to quantum attacks.
Osuntokun says the testing is far from optimization and that more efficient and smaller circuits will be used in production implementations. Its current purpose is to demonstrate that: This solution is technically feasible with currently available hardware.
Background: Taproot progresses in the opposite direction.
As reported by CriptoNoticias, Taproot addresses are showing signs of becoming obsolete in the Bitcoin ecosystem, a phenomenon that may be related to its quantum vulnerability.
Taproot addresses expose public keys directly on-chain and are therefore a direct target of Scholl’s algorithm. A sufficiently powerful quantum computer can use the published public key to derive the private key and access the funds.
Finally, as eloquent evidence of Taproot address underutilization, data from the Clarkmoody platform currently shows that Only 10% of all Bitcoin addresses support Taproot format.
