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Signing a Bitcoin Transaction with Lamport Signatures (no changes needed)

Signing a Bitcoin Transaction with Lamport Signatures (no changes needed)

Original Postby Ethan Heilman

Posted on: April 30, 2024 13:25 UTC

In discussing the implications of quantum computing on cryptographic security, particularly in relation to Bitcoin, it's acknowledged that a quantum computer could drastically alter the effectiveness of current signature schemes.

The conversation highlights a vulnerability in ECDSA (Elliptic Curve Digital Signature Algorithm) signatures, where an attacker with access to quantum computing could efficiently find a specific value (denoted as "k") that compromises the security of the signature. This vulnerability stems from the ability to efficiently compute discrete logarithms with quantum computing, making certain attacks more feasible.

However, a potential mitigation strategy for this vulnerability has been proposed, stemming from discussions within the digital currency community. It was suggested that by universally adopting a fixed value of "r=1" for signatures, the system could be safeguarded against these quantum-enabled attacks. This approach leverages the fact that, under certain conditions, ECDSA signatures can be validly generated with both "r" and "s" values set to 1, circumventing the need for traditional computation that would be vulnerable to quantum decryption methods. This method benefits from the intrinsic properties of ECDSA, where a signature does not inherently prove the knowledge of a discrete log, thus providing a theoretical workaround to quantum vulnerabilities.

Despite these discussions, there remains a significant challenge in fully protecting Bitcoin from quantum attacks without resorting to a soft fork that introduces new functionalities, such as disabling key-spend paths in taproot outputs. The necessity of such a soft fork underlines the current limitations in making Bitcoin quantum resistant through existing mechanisms alone. The dialogue within the community continues, with hopes that further research and innovation will eventually overcome these hurdles.

For more detailed discussions on the topic and the technical nuances involved, refer to the ongoing conversation on Bitcoin forums, specifically at this link.