Unsolved
Bitcoin puzzle #121
Bitcoin puzzle #121 is unsolved. It holds 12.10 BTC, and its private key is an unknown number between 2120 and 2121−1 — a keyspace of 1.32 × 1036 possible keys. You can search that range with the solver below; it runs in your browser and never sends anything to a server.
Solver — #121
IdleJump to a random point in the range, sweep a block of keys, jump again. Best when many people search the same puzzle.
Each thread is one Web Worker on one core. Leaving a core free keeps the page responsive.
Walk the range in order from your start key up to the end of the range, splitting that region evenly across threads. Keys below the start key are not searched. Best when you are coordinating a systematic sweep.
Range covered: 0%
· Current key: 1000000000000000000000000000000
Puzzle #121 at a glance
- Reward
- 12.1 BTC
- Address
- 1GDSuiThEV64c166LUFC9uDcVdGjqkxKyh
- HASH160
- a6e4818537e42f7b3f021daa810367dad4dda16f
- Range start
- 1000000000000000000000000000000
- Range end
- 1ffffffffffffffffffffffffffffff
- Bit length
- 121-bit
- Keys in range
- 1.32 × 1036 (1329227995784915872903807060280344576)
- Transactions
- 3
The arithmetic
The range for puzzle #121 contains 1.32 × 1036 private keys. A modern eight-core laptop running this solver checks on the order of four million keys per second, so an exhaustive sweep would take about 1..0 × 1020 years. Searching randomly instead of in order does not change that expectation — it only changes which unlucky order you fail in.
Puzzle #121 — common questions
How many private keys does Bitcoin puzzle #121 contain?
Puzzle #121 spans the range 2^120 to 2^121−1, which is exactly 1.32 × 10^36 private keys — twice as many as puzzle #120.
How long would it take to solve Bitcoin puzzle #121?
An eight-core machine running this browser solver at four million keys per second would need about 1..0 × 10^20 years to sweep the whole range. A pooled GPU cluster reaching one trillion keys per second would need about 4.21 × 10^16 years.
How much is Bitcoin puzzle #121 worth?
The address holds 12.1 BTC, roughly $946,885 at a reference price of $78,255 per BTC.
Is Bitcoin puzzle #121 solved?
No. #121 is one of the 78 unsolved puzzles. Its public key has never been exposed, so square-root methods like Pollard's Kangaroo do not apply — brute force over the range is the only option.
What is the key range for puzzle #121?
From 1000000000000000000000000000000 to 1ffffffffffffffffffffffffffffff in hexadecimal. The address is 1GDSuiThEV64c166LUFC9uDcVdGjqkxKyh and its HASH160 is a6e4818537e42f7b3f021daa810367dad4dda16f.