This mischief-maker is out to prove that blockchain is not as secure as crypto-enthusiasts say it is.

Look out for a message saying Einsteinium has been hacked and double-spent with all the details. Cross your heart and hope to die. That’s a Reddit user‘s promise. He’s been offered $800 to fulfill his bet.

“Hey all,” someone called team-periwinkle told his Reddit team, “On Oct 13, 3:00 CDT, 4:00 EDT 1:00 PST I’m going to do a 51% attack against the cryptocurrency Einsteinium. I’m putting in $50 of my money and if you want to donate you can.”

The hacker, also called @geocold51 on Twitter, told Reddit he’ll be live-streaming his performance on Twitch so viewers can catch him in the act.

If you think Einsteinium is easier to breach than Bitcoin, Bitcoin Gold (one of Bitcoin’s arteries) experienced a 51% attack in May, where one or more hackers seize control of about 51% of the blockchain’s computing power.

If you think that’s no big deal, think again.

Blockchain has long touted itself unhackable, insisting you need an incredible and impossible amount of hashing power to breach its ledger and that participants/nodes would instantly defend the network. That’s how it persuades people to invest in its technology. Your money and valuables, it tells them, are safe on the blockchain ledger since the ledger can never be hacked.

For the same reason, it assures us that the blockchain prevents double spending, where your same single digital coin is spent no more than once.