The puzzle's anonymous creator and the true purpose of the challenge have spawned years of speculation. Here are the main theories, with evidence for and against.
🎯 "Crude measuring instrument"
Theory: saatoshi_rising stated the puzzle is "simply a crude measuring instrument of the cracking strength of the community." The goal is to benchmark how fast the ecosystem can crack keys of increasing difficulty.
Evidence for: The creator's own words. The 2019 public-key reveals support this — they wanted to test whether kangaroo algorithms could crack higher ranges. The 10× reward increases keep the incentive alive as hardware improves.
Evidence against: Sending ~1000 BTC (~$60M+) just to "measure" cracking strength is extraordinarily expensive for a benchmark.
🟧 Satoshi connection
Theory: A BitcoinTalk thread proposes that saatoshi_rising is Satoshi Nakamoto, and the puzzle's early mined coins are a "prize competition" — Satoshi is waiting for someone to move the coins as a signal.
Evidence for: The username contains "satoshi." The puzzle started in 2015, years after Satoshi's disappearance. The scale (1000 BTC) suggests someone with enormous early holdings.
Evidence against: If Satoshi were hiding, choosing a name containing "Satoshi" would be counterproductive. The puzzle keys are explicitly low-entropy — nothing like Satoshi's actual mining keys. Community consensus: unlikely.
💡 Educational demonstration
Theory: The puzzle exists to demonstrate the vastness of Bitcoin's private key space. Even a 66-bit key (trivially small by Bitcoin standards) took years to crack, proving that standard 256-bit keys are computationally unbreakable.
Evidence for: The creator's quote supports this interpretation. The progressive difficulty makes the point visually and mathematically. It's a living proof of Bitcoin's security.
Evidence against: Doesn't explain why the creator keeps adding funds (872 BTC in 2023). A one-time demonstration wouldn't need ongoing investment.
🔮 Quantum canary
Theory: The puzzles with known public keys (135, 140, 145, 150, 155, 160) serve as a "quantum canary." If someone suddenly solves a high-numbered puzzle with a known public key without brute-forcing, it could indicate quantum computing has advanced enough to break elliptic curve cryptography.
Evidence for: The 2019 public key reveals specifically targeted high-numbered puzzles where brute force is infeasible. The puzzle structure naturally tests the boundary between classical and potential quantum attacks.
Evidence against: Pure speculation. The reveals could simply be for testing kangaroo algorithms. No quantum computer today can break 135-bit ECDLP.