delvingbitcoin

Non interactive anti-exfil (airgap compatible)

Non interactive anti-exfil (airgap compatible)

Original Postby moonsettler

Posted on: August 21, 2024 14:06 UTC

The discussed protocol exposes a vulnerability to low bandwidth attacks through nonce point churning, posing significant challenges for low power devices.

These devices face difficulties in performing continuous double point multiplications and hash operations while managing the complexities of tracking leaked seed parts. This task is further complicated by limitations on firmware modifications and the need for intricate pseudo-random indexing schemes, which add to the operational burden.

Moreover, the effectiveness of such attacks is highly questionable due to the inherent risks and challenges involved. Routine validation tests performed by factories or users—designed to verify the integrity of the Q generation process against standards like RFC6979—serve as a robust defense mechanism. These tests are likely to detect any anomalies associated with continuous attack attempts, making the strategy highly risky for the attacker. The low probability of success combined with the high risk of detection during standard operational testing makes this attack vector impractical for most adversaries.

There is also an ongoing discussion among experts about the potential integration of additional proof-of-work mechanisms to mitigate or entirely neutralize the threat posed by low bandwidth leaks. Such measures would aim to increase the computational and time requirements for generating signatures, leveraging known hardware capabilities to identify and prevent nonce churning. This approach suggests a proactive stance towards enhancing security protocols, ensuring that attacks exploiting firmware vulnerabilities become increasingly difficult to execute without detection.