Adam Back Kills Bitcoin Quantum Threat With New Taproot Showcase - U.Today

The safety of Bitcoin (BTC) and other assets from quantum threats has again resurfaced in the cryptocurrency space, with notable stakeholders and cryptographers brainstorming on it. A conversation initiated by an author and developer with the username Hunter Beast has elicited comments from Blockstream CEO Adam Back.

Adam Back argues “Taproot feature” enough for Bitcoin

According to Back, there is no need to redesign Bitcoin over concerns about a hypothetical future threat. “But why?” he queried.

The Blockstream CEO argued that there was no need for BIP 360’s proposed P2TSH output type, arguing that Taproot was designed for quantum readiness. He explained that its key tweak recently confirmed it was secure against post-quantum attacks.

Back insisted that if a serious threat ever appeared in the form of Cryptographically Relevant Quantum Computers (CRQC), Bitcoin could simply disable key-path spends. He maintained that relying on “hashed public keys” for quantum safety was theoretical, not practical.

He argues that key reuse is everywhere as many wallets utilize addresses, index servers and unhardened HD derivation. As such, even if Bitcoin is switched to hash-only schemes, quantum attackers would still have plenty of exposed keys to target.

Back believes that Taproot is already good enough to safeguard Bitcoin from quantum threats, as that was the intent of the design. He considers BIP 360 as premature and overly disruptive, and would prefer increased adaptation only when quantum threats are real.

Interestingly, Hunter Beast and other advocates of BIP 360 want stronger post-quantum guarantees and are willing to sacrifice Taproot features now.

However, there are concerns that Bitcoin could lose public key tweaking and Point Time-Locked Contracts necessary for advanced Lightning and Smart contract constructions.

Although Hunter Beast acknowledged it could be lost, it would be possible to work around it by using isogeny-based cryptography in the future.

Other stakeholders dismiss quantum threats

Despite the ongoing debate, Adam Back has always dismissed quantum threat fears. He opines that Bitcoin’s security is about signatures, not encryption. Back also insists that there are no immediate threats from quantum computers⁠⁠⁠⁠⁠⁠⁠, as many suggest.

He claimed the unnecessary fears surrounding the topic are from those who do not fully appreciate how Bitcoin’s network operates. Back estimates that Bitcoin is unlikely to face any serious quantum computing threat in the next 20 to 40 years.

Similarly, JAN3 CEO Samson Mow, known for predicting Bitcoin could hit $1 million, says there is no need to worry about quantum computers killing the asset.