An anonymous user solved the puzzle on 7 ETH

An unknown user received 7 ETH (~4200 at the time of writing) for solving a puzzle that started with a billboard in the Warsaw metro. Decrypt writes about it.

An advertisement with an Ethereum address and hashtags #0xPOLAND and #0xPOLANDHEIST appeared at one of the stations. It called on passengers to solve a puzzle to pick up 7 ETH.

According to the organisers, the Ethereum contract code required a „solve“ function to be called up and a secret phrase to be used to withdraw the funds. The prompts were published in a Twitter account called 0xPoland.

The first one contained the phrases „Tip: ^[A-Z].*.“ and „0x01ccfbfc“. One said that the message should start with a capital letter and end with a dot, while the other was about a part of the checksum.

There was a quote in the image attached to the tweet. She pointed to the song title of the Elffor music project. The participant had to get the first part of the secret phrase – „into the dark forest“.

A few days later, 0xPoland published another tweet. The phrase hinted at the work ‚Hitchhiking across the Galaxy‘, and a string of symbols required the quest participant to have programming skills. The result was the second part of the code – „down the rabbit hole“.

The final hint appeared in print and electronic versions of the Gazeta Wyborcza.

„A lot of daily newspapers rejected our announcement because they could not understand the concept of the puzzle and preferred to reinsure themselves,“ said the organisers of the quest.

The ad contained a telephone number. The participant received a recorded message with the missing parts of the secret phrase, which looked like it in full form: „From 0xPoland. Into a dark forest. In the rabbit hole. Where adventure awaits you.“.

The correct answer was recorded in the smart contract 21 minutes after the tweet was published.

The organisers explained that they were so keen to invite developers to join their team „to create a decentralised financial infrastructure“.

In January 2019, street artist Pascal Boyart drew a mural with an encrypted puzzle for 0.26 BTC (about $1055 at the rate at that time) to mark the 10th anniversary of the Bitcoin genesis block.

Less than a week later, two Twitter users found 12 words to access their reward wallet.

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