Post #18079

Links for 2026-03-31 [Part 2] Quantum and Crypto 1. Google Quantum AI’s new whitepaper argues that quantum attacks on the elliptic-curve cryptography used by Bitcoin and Ethereum may require far fewer resources than many people assumed. For secp256k1, the authors report Shor-algorithm circuits using either about 1,200 logical qubits and 90 million Toffoli gates or about 1,450 logical qubits and 70 million Toffoli gates, and they estimate that under favorable superconducting-hardware assumptions these attacks could run in minutes with fewer than half a million physical qubits. The most novel part is their disclosure method: instead of publishing the full attack optimizations, they provide a zero-knowledge proof showing that they really do possess a circuit of the claimed size for the key elliptic-curve point-addition bottleneck, allowing outsiders to verify the resource estimate without handing would-be attackers a full blueprint. For Bitcoin, the paper’s big implication is that sufficiently fast “fast-clock” quantum machines could eventually enable “on-spend” attacks, where a public key exposed during a transaction broadcast is cracked before confirmation, while older exposed keys and dormant coins remain an even bigger long-term target; the authors therefore argue that migration to post-quantum protections should begin urgently. https://quantumai.google/static/site-assets/downloads/cryptocurrency-whitepaper.pdf 2. Oratomic’s paper makes the complementary claim that the physical-hardware cost of cryptographically relevant Shor attacks may also be much lower than standard surface-code estimates suggest, at least for neutral-atom machines with reconfigurable connectivity and high-rate qLDPC-style error correction. The authors say Shor’s algorithm could in principle run with as few as 10,000 atomic qubits, and that an architecture with roughly 26,000 physical qubits might solve ECC-256 discrete logs in around 10 days under a 1 ms stabilizer-cycle assumption, with RSA-2048 taking much longer. The point is not that Bitcoin can be broken tomorrow—this is still a theoretical resource estimate with major engineering hurdles—but that the hardware gap may be shrinking faster than expected if nonlocal neutral-atom architectures and better codes work as hoped. For Bitcoin and similar systems, that strengthens the broader message from the Google paper: even if neutral atoms are too slow for near-real-time mempool attacks, they could still threaten long-exposed public keys and dormant funds, reinforcing the case for post-quantum migration well before such machines actually exist. https://arxiv.org/abs/2603.28627 3. Automated near-term quantum algorithm discovery for molecular ground states https://arxiv.org/abs/2603.26359 Physics 1. Causality optional? Testing the “indefinite causal order” superposition https://arstechnica.com/science/2026/03/getting-formal-about-quantum-mechanics-lack-of-causality/ 2. “I Built Feynman’s Reverse Sprinkler To Solve 140 Year Old Mystery” https://www.youtube.com/watch?v=G5DzkVI4EQE 3. For decades, the original paper which introduced something called the see-saw mechanism for neutrino mass was overlooked in favour of subsequent papers by more famous physicists. https://blog.inspirehep.net/2013/06/sleeping-beauty/ Psychology & Neuroscience 1. Open Access Book: Decision Making under Deep Uncertainty https://link.springer.com/book/10.1007/978-3-030-05252-2 2. “Slack”—defined as the absence of binding constraints or having free capacity/space—is essential for any system or agent to be effective. https://www.lesswrong.com/posts/nQd64RC5vXyqiFZLD/slack-in-cells-slack-in-brains 3. Thalamic activation of the visual cortex at the single-synapse level https://www.science.org/doi/full/10.1126/science.aec9923 4. A neural algorithm for a fundamental computing problem [published in 2017] https://www.science.org/doi/10.1126/science.aam9868 5. Cerebellum as a kernel machine: A novel perspective on expansion recoding in granule cell layer [published in 2022] https://pmc.ncbi.nlm.nih.gov/articles/PMC9815768/