Bitcoin puzzle bounty reaches $58.9M

• Unsolved Bitcoin puzzle addresses now hold approximately 916 Bitcoin worth about US$58.87 million.
• Community trackers show 82 of 160 puzzle addresses have been solved, leaving 78 still active.
• Puzzle 71 is currently the lowest-numbered unsolved challenge, carrying a reward of about 7.1 Bitcoin.

A long-running Bitcoin (CRYPTO:BTC) puzzle challenge now holds approximately 916 BTC worth about US$58.87 million across 78 unsolved addresses, according to community tracking data.

The challenge began in January 2015 with 256 funded addresses containing a combined 32.896 BTC, before later consolidations reduced the active puzzle set to 160 addresses.

Community records indicate that 82 puzzles have been solved so far, leaving 78 remaining, while the total reward pool expanded significantly after prize values were increased in 2023.

The current lowest-numbered unsolved address-only challenge is Puzzle 71, which offers approximately 7.1 BTC and requires searching a private key range between 2^70 and 2^71.

Tracking data published on June 23 showed participants had covered about 0.864% of the assigned search space at an average rate of 57.3 billion keys per second, with a projected completion time of roughly 422 years if current rates remain unchanged.

The remaining challenges are divided between address-only puzzles and puzzles with publicly known keys, with the latter allowing the use of specialised algorithms such as Pollard's Kangaroo method to reduce computational complexity.

Developers and participants commonly use software including BitCrack, Keyhunt and Kangaroo to search for keys, while community-operated pools coordinate computing resources by assigning search ranges to contributors across the network.

At the time of reporting, Bitcoin price was $62,611.46.