How the shared search for the 7.1 BTC key works
Together we are searching for the key to Bitcoin Puzzle #71. Anyone can help from a phone, and every piece searched shows on one shared map.
Open the map and startPuzzle #71
In 2015 an anonymous author put bitcoins on a series of addresses whose keys are hidden in ever larger ranges. The higher the puzzle number, the bigger the field and the bigger the prize. The address of puzzle #71 (1PWo3JeB9jrGwfHDNpdGK54CRas7fsVzXU) holds 7.1 BTC. Its key is one number between 270 and 271, more than a trillion billion possibilities.
There is no shortcut: the only way to find the key is to search. So whoever checks more wins. We decided to search together and honestly, on a shared map that shows everything already covered.
The map and plots
The whole field is split into 4,294,967,296 plots of about 275 billion keys each. A plot is split into 1024 steps. A step is 268 million keys: a phone does one in a minute or two, a graphics card does a whole plot in a few minutes.
On the map:
- dark — nobody has searched here yet;
- glow — some steps are done, and the brighter, the more;
- red — the plot is fully searched, all 1024 steps, no need to come here;
- green — someone is searching here right now.
A place named by four words
A plot number is hard to remember, so every plot has a name of four simple words: animal or bird · plant · object · nature.
Albatross · Birch · Compass · Rainbow
The first word is a large district of the map, the second a quarter inside it, the third a street, the fourth the plot itself. You can pick a place on spinning drums, like a riddle: your animal, your tree, your object, your element. It is easy to share: “I searched Albatross · Birch · Compass · Rainbow”. Each language has its own word lists, but the plot number is the same, so people in different countries name the same place in their own words.
The four-word place naming scheme was created by the Lucky Day project. On 12 October 2026 its description and word lists were timestamped in the Bitcoin blockchain (OpenTimestamps).
Why it is honest
- Control keys. Every step contains hidden check keys. A step counts only if the device found all of them, so work cannot be faked.
- Once and for all. A searched plot is marked on the shared map and never checked again. No duplicated work.
- An open map. Everyone can see what has been searched, by whom and how much.
If the key is found
The key never appears on screen. The page or app immediately encrypts it with the project's public key, and only the project can decrypt it. This protects against bots: a normal broadcast of such a prize gets front-run within seconds. So the prize is claimed through a private miner and shared by the rules:
For every friend you invite, you get a bonus from the project share: 10% of their steps.
Honest odds
It is a math puzzle with a prize: one plot is one chance in 4.3 billion, and we say so plainly. But nothing is wasted: every searched step shrinks the field for everyone, for good.
Questions
Do I need to install anything?
No. Open the site in a browser or in Telegram (@luckydaycloudbot). GPU owners can install the Lucky Day Worker app: it searches a whole plot in a few minutes.
Will it harm my phone?
The phone works as under any normal load, like a game. You can lower the number of threads. The easiest way is to leave the search running overnight while the phone is charging.
Can I stop at any time?
Yes. Only the unfinished step is lost, everything searched stays yours.
Why sign in with Telegram?
So your steps are credited to you and visible from any device, and invited friends are counted. We never receive your phone number.
Open the map and start