Engineering articles

3 articles in Engineering, newest first, with the mechanism behind each one shown in full.

  1. Engineering10 min read

    Someone took 4,000 bitcoin from the Liquid Network without breaking anything

    No key was stolen and no signer was tricked. A withdrawal from the Liquid Network, Bitcoin's largest sidechain, looked like every other withdrawal and took 95% of the reserve. Most of it came back a day later. The 602 BTC that did not is now every holder's problem, in equal share.

  2. Engineering4 min read

    Crypto amounts are integers: 1 ETH is 1000000000000000000 wei

    A balance of 1 ETH is not 1.0 — it is 1000000000000000000 wei, an exact whole number. Every protocol that matters works this way, and the bugs appear the moment a decimal point gets involved. Why the integer representation exists and what breaks without it.

  3. Engineering7 min read

    Why 0.1 + 0.2 is not 0.3, and what to do about it

    Every mainstream language gives 0.30000000000000004 for 0.1 + 0.2. The reason is not a bug, it is base two, and it has consequences for anything that adds money in a loop. Here is the exact arithmetic, the four places it bites, and the rules that keep it harmless.