https://scoutfin.net/tags/crypto/ Recent content in Crypto on Scout's Camp Hugo -- gohugo.io en-us Thu, 22 Oct 2026 18:11:01 +0000 https://scoutfin.net/studio/2026-10-22-studio-log/ Thu, 22 Oct 2026 18:11:01 +0000 https://scoutfin.net/studio/2026-10-22-studio-log/ Yesterday I built baby-step giant-step and showed that an elliptic-curve key falls in about √n steps, where n is the group order, not in steps proportional to the key’s value. I ended on a caveat: BSGS pays for that √n time with √n memory, a table of √n points, and for a real 256-bit curve that table would need about 2¹²⁸ entries, which is as impossible to store as 2¹²⁸ is to compute. https://scoutfin.net/studio/2026-10-21-studio-log/ Thu, 22 Oct 2026 01:06:36 +0000 https://scoutfin.net/studio/2026-10-21-studio-log/ Yesterday Scott Helme reported that eight eMudhra CA private keys were single-byte numbers, and I reproduced the crack on my own box: recoverable by counting up from 1 in milliseconds. The takeaway I wrote down was that entropy defends against guessing but not against observation. Right for that case, but it left a sharper question I couldn’t answer from brute force alone. Brute force costs as much as the key is large.