[7]

Hi 7!

First of all, sorry for spoiling the fun. I was the one who cracked the wallet. Sorry just now I was afraid of some backlash from fellow hunters.

I had been preparing for this challenge for several days because I expected the real race to begin once 9 out of 12 words were revealed.

While it’s true that 3 missing BIP39 words correspond to roughly 8.6 billion combinations, it’s not as impossible as it first appears.

My approach

I first wrote a CPU-based recovery script. It achieved only around 90–110k candidates/sec, which meant a full 3-word search would take far too long. I knew that by the time the 10th word was revealed, other players would likely finish before me.

Then I remembered that my machine has an RTX 3070. My original implementation wasn’t actually utilizing the GPU properly, so I rewrote and optimized it to run on the GPU instead.

Another optimization came from the BIP39 checksum.

For a 12-word BIP39 mnemonic:
Total entropy: 128 bits
Checksum: 4 bits

This means only 1 out of every 16 possible mnemonics has a valid checksum. My script took advantage of this and only performed the expensive seed derivation on checksum-valid candidates, reducing the work by roughly 16×.

Instead of testing the full ~8.6 billion combinations, it only needed to process about 536 million checksum-valid candidates.

I still wasn’t completely confident in my riddle answers, but I decided to give it a shot anyway.

For anyone who wants to verify that I was indeed the one who recovered the wallet, here’s the mnemonic:

protect cigar sphere father nephew still toe maximum nasty among differ game

Thank you for the fun riddles, 7! I hope this won't ban me from participating in V5 :(

Ofc not and I am very happy to see you shared your method and came forward. I hope you stick around on the forum and definitely for the next round.

[Three]

Hi 7!

First of all, sorry for spoiling the fun. I was the one who cracked the wallet. Sorry just now I was afraid of some backlash from fellow hunters.

I had been preparing for this challenge for several days because I expected the real race to begin once 9 out of 12 words were revealed.

While it’s true that 3 missing BIP39 words correspond to roughly 8.6 billion combinations, it’s not as impossible as it first appears.

My approach

I first wrote a CPU-based recovery script. It achieved only around 90–110k candidates/sec, which meant a full 3-word search would take far too long. I knew that by the time the 10th word was revealed, other players would likely finish before me.

Then I remembered that my machine has an RTX 3070. My original implementation wasn’t actually utilizing the GPU properly, so I rewrote and optimized it to run on the GPU instead.

Another optimization came from the BIP39 checksum.

For a 12-word BIP39 mnemonic:
Total entropy: 128 bits
Checksum: 4 bits

This means only 1 out of every 16 possible mnemonics has a valid checksum. My script took advantage of this and only performed the expensive seed derivation on checksum-valid candidates, reducing the work by roughly 16×.

Instead of testing the full ~8.6 billion combinations, it only needed to process about 536 million checksum-valid candidates.

I still wasn’t completely confident in my riddle answers, but I decided to give it a shot anyway.

For anyone who wants to verify that I was indeed the one who recovered the wallet, here’s the mnemonic:

protect cigar sphere father nephew still toe maximum nasty among differ game

Thank you for the fun riddles, 7! I hope this won't ban me from participating in V5 :(

Congratulations.

You explaining how you won made the competition even more enjoyable.

I had assumed you were doing it using a rented GPU—like a rtx 4090 or something even more powerful. But I have to say, I was surprised to learn you're doing this with a rtx 3070 at home. Not everyone has a graphics card like that at home.

Also,

protect cigar sphere father nephew still toe maximum

I guessed correctly up to this point.

"nasty" wrong for me.

7 Thank you again for organizing such a competition. Honestly, I enjoyed it because I correctly guessed the first eight words.

---

Also, if a v5 competition is held, everyone will need to rent a powerful GPU, because there is a 24 hour gap between the release of the 9th word and the 10th word.

[7]

You all ready for the next on. I think its time to spice things up!. lets get more of the public coming on and I really hope this guy stick around.

[Austin0965]

Congrats, great hunt. I hope to win the next one lol

[Fr3d]

This game is really good. If a V5 is coming, please make sure the puzzle solutions can't be brute-forced or cracked by a computer. I'm actually waiting for the 12th riddle right now

[7]

Im going to close this one. Click on my profile and follow me to make sure you get full updates of any further competitions.