Two months after announcing the launch of its application Juggernaut of instant messaging at Lightning Network, the developer John Cantrell, admitted to having been the one who discovered the key to access the wallet, bitcoin entrepreneur in the world of cryptocurrencies, Alistair Milne.
The details of the exploits with which he won 1 bitcoin (USD 9.400 at that time) were published by Cantrell, in an article for his blog on Medium, where he stated that tried out a zillion words to decrypt the key that allowed him to complete the challenge.
It was not a robbery, which Cantrell did was win a challenge launched by Milne at the end of may. Through his Twitter account, the CEO of Altana Digital Currency Fund invited to earn 1 bitcoin that he had deposited in her purse. The award would be in the hands of the first to bring together the 12 words of the phrase seed with which you would access to the portfolio.
To comply with what was promised, Milne periodically revealed a new track. Had been informed that the last four keywords would be launched simultaneously with the idea of preventing someone from hackeara the portfolio. However, before publishing the eighth word, the entrepreneur discovered that his plan had failed, because by that time, Cantrell had guessed the other words, found the right combination and transferred the funds to your own wallet.
Sizing the problem
To achieve its objective, Cantrell described in his article that he prepared just before it was revealed the eighth track. I knew that one phrase vanity or seed, is generated using 2048 words of a fixed list. Without the hints revealed by Milne, the task appeared almost impossiblebut the chances of success are increased if he knew some of the words that the owner of the portfolio published on their social networks.
“Luckily, we don’t need to check all the possibilities of 212⁸ because Alistair was going to publish a keyword every two days. Each word that we collect reduces the possibilities we need to check by a factor of 211, or 2048,” noted Cantrell.
Cantrell spent days and nights to design a plan that would allow him to earn bitcoins. Source: Pexel
The developer added that with eight words there would be around 1.1 trillion phrases mnemónicas possible to verify. I also needed to generate a private key teacher from the seed and an address from the private key teacher. But after several tests it turned out that the computer that I had, at that time, was not suitable for this task.
The laptop of the developer I could only check about 1250 phrases mnemónicas per second, that is to say, 108 million phrases per day. “That meant that my CPU, it would take approximately 25 years to build and test more than a trillion possible phrases to open the purse, with only eight words at your disposal,” wrote Cantrell in his publication.
To speed up the process, the developer paid about $ 350 for a service of rental of computing power. But not had as good luck. After checking the 85% of the combinations, failed to find the correct one. It was then when he realised that he needed to revise his method to determine where was the mistake.
Giving with the solution
An in-depth review allowed to verify the success of the plan that was being implemented, until then, depended on the selection of the words in the correct order, which was not guaranteed by the method used. Even came to lose hope that it would work and thought of giving up.
“But I could not stop after coming so far. To my surprise, a little later that night, when the 91% of all the sentences were reviewed, and after nearly 30 hours, we found the correct phrase,” added Cantrell.
Once that Cantrell had access to his wallet, he paid a high commission of 0.01 BTC (USD 93) for the miners to confirm your transaction faster, because they feared that someone else could hack the wallet before him. Later, the own Milne confirmed the withdrawal of 1 BTC in your wallet.
“I woke up with some “bad” news this morning. The wallets of 1BTC has been enforced brutally, which is pretty awesome. I should have rented several GPU to do it so fast! I knew I was going against the clock, but most of the people thought that it would take a few weeks to collect the 4 key words remaining,” said Milne in his Twitter
After almost abandon his project, Cantrell managed to decrypt the key and transferise a bitcoin. Example of seed portfolio. Source: https://wiki.trezor.io
In his article, Cantrell says that having the tracks revealed by Milne facilitated his task, that even so it was complicated. Even Milne was invited to read the article by Cantrell to the point: “for those who think that hacking a portfolio is easy, read this thread. I knew that every word that he revealed made it 2048 times easier for a brute-force attack”.
As well as Cantrell revealed the keys to hack a wallet of bitcoin, the developer, Jameson Lopp, two years ago, he recommended eight steps “home” to keep the savings of cryptocurrencies safe from thugs. As reported Breaking News, Lopp indicated that the first step to insure savings deposited in a wallet bitcoin and other cryptocurrencies, is to create a file-encrypted or hiding such information through the application of VeraCrypt, a tool open source that allows you to encrypt and hide data in a simple way.
The achievement of Cantrell demonstrates that in the era of the cryptocurrencies it is necessary to remain cautious with regard to the safety of the moneros and never to disclose any information linked to them, much less through the social networks.