Bitcoin and Lightning Network project developer, John Cantrell, explained how he was able to successfully hack a BTC address by checking around a trillion seed combinations over the course of 30 hours. The feat was accomplished as part of a contest launched on Twitter by Alistair Milne — the CIO of the Atlanta Digital Currency Fund.

Milne published hints to a 12-word Bitcoin wallet seed over the course of several days. Cantrell succeeded in brute forcing the mnemonic with only 8 out of the 12 words, ultimately claiming the 1 BTC prize contained inside.

Developer rented several graphics cards

Cantrell decided to rent several graphics cards through GPU marketplaces and Microsoft’s Azure cloud computing service after realizing that his Macbook could only check 1,250 mnemonic combinations per second using his self-written CPU seed solver.

The developer explained:

“I was worried about other people doing the same and is why I included a .01 BTC miner fee. I didn’t think even this would be enough and thought there could be a ‘race to zero’ where people continually increased the fee trying to get the miners to include their transaction in the next block.”