Basics
A total of 969 BTC (approximately $65 million at the time of writing) is distributed across 75 Bitcoin wallets, known as Bitcoin puzzles. Anyone who manages to decipher the private keys can claim the bitcoins.
Origin and Mystery of Bitcoin Puzzles
On January 15, 2015, an anonymous individual distributed 32.9 BTC among 256 addresses, with the first receiving 0.001 BTC, the second 0.002 BTC, and so forth up to 0.256 BTC. Users on Bitcointalk noticed a pattern in the transactions: the private keys to the addresses in binary format started with decreasing numbers of zeroes. The creator's identity remains unknown, though occasional actions hint at their involvement. In 2017, bitcoins were moved from addresses #161 to #256 to "younger" addresses, likely due to the increasing difficulty of finding keys longer than 160 bits in the foreseeable future.
Why Do We Call Them Puzzles?
The community speculates that the puzzle's creator aimed to showcase Bitcoin address resilience to key cracking. Users view cracking the puzzles as a challenge with rewards, rather than an attempt at theft. The anonymous figure actively maintains community interest by periodically enhancing rewards. As of publication, 75 puzzles remain unsolved, containing balances ranging from 6.6 BTC (approximately $442,200) to 16 BTC (approximately $1,072,000), totaling 969 BTC (approximately $65 million).
Decrypting Bitcoin Puzzles: Strategies and Tools
To solve a Bitcoin puzzle, one must uncover the private key linked to the respective address.
Within the first day, users cracked 29 puzzles. The time to crack addresses #40, #47, and #64 ranged from two weeks to five years. The simplest unsolved puzzle contains 66 random bits, yielding approximately 7.37 * 10^19 possible combinations. Even with a GTX 1660 Ti GPU checking a billion variants per second, it would take around two thousand years to exhaustively search this range.
Community members have developed numerous tools to solve puzzles, such as Private Key Finder, KeyHunt, and BitCrack. Additionally, joining the 66 Bit Collective pool can enhance chances of success by distributing the search workload.
How Were Bitcoin Puzzles Created?
Following the steps of the anonymous creator in 2015:
- Generate 256-bit strings with random bits ranging from 1 to 256.
- Turn each string into a private key using the cryptographic formula of the selected blockchain.
- Generate public addresses.
- Send tokens to them. The size of the rewards should match the number of random bits in the key.
Experience with Bitcoin puzzles suggests that cracking keys with 60 or more random bits could take several years. To sustain interest, the creator used multiple addresses with fewer random bits and smaller rewards, instead of increasing rewards for each additional bit.
Conclusion
Bitcoin puzzles offer a unique challenge, with 969 BTC spread across 75 wallets. Originating from an anonymous distribution in 2015, these puzzles intrigue the community with their resilience to key cracking. Despite efforts, many puzzles remain unsolved, showcasing their complexity.