How To Double Spend Bitcoin

So I was trying out a Google adwords campaign recently, with keywords like “51% attack”, “double spend”, “eclipse attack”, and more. Do you know what the #1 search is for people who are interested in these topics, and, decide to type them into the magic google search bar? “how to double spend bitcoin”. Yep. Or some form of that, like “bitcoin double spend tool”, or “suggest methods for bitcoin double spend”.

So let’s dive into this topic a little, shall we? First, what is a double spend? In a few words, it’s just being able to spend a digital token or cryptocurrency twice. Since it involves the same coin, it, in effect doubles the purchaser’s spending power by creating a false transaction with funds that have already been spent. It undermines the underlying blockchain, dilutes the existing supply of currency, but, gives the perpetrator some free cash, so, it becomes a lucrative way to steal funds. The most profitable way it is done is in conjunction with a 51% attack. And it involves going Back to the Future.

For the google searchers, sorry to disappoint, but, it is really extremely tough to do this with Bitcoin. And there’s no easy tool to download to be able to pull off a double spend. You have to know a little something about hash power, how to get a whole lot of it, and the underlying node configuration of the blockchain you’re targeting. But, before you hit the back button, continue reading, you may just learn something!

A 51% attack basically goes back in time, and re-writes a blockchain, and the transaction history that is written on it, by overpowering more than half the network of nodes, creating a new set of blocks, and validating them as the “right” set. So, one way to double spend is to dump funds from a wallet onto an exchange, sell them for something else, then, go back, re-write the history by sending the same funds to another address, and then selling those. Be warned though — it is not only highly unethical, but potentially illegal to do so. But yet this type of thing happens quite a bit, unfortunately, to vulnerable blockchains, and, a large amount of crypto gets stolen each year, with little recourse. I can think of an incident just a few days ago, where someone re-wrote 7000 blocks of a major crypto chain, about 2 days worth on this chain, and it wasn’t the first time. These things get written off as “chain re-orgs”, when the real word for it should be “theft”.

There is a solution to this problem though, and, in my opinion, the best solution on the market right now for this sort of thing. SafeNodes, a product offering by SafeCoin, use a delayed Proof of Work system of notarizing transactions to multiple blockchains, using the MATCH protocol, thereby severely reducing the risk of a double spend on a blockchain. A fleet of notary nodes stands ready to harden your chain against a 51% attack. Someone would have to rewrite the history of not only your blockchain, but also that of a few others. Simultaneously. Without being detected by any of them. Not likely.

In summary, just another way to say:

For more info, hit up SafeCoin on Discord. Whether you’re looking for protection for your blockchain, or you’re a hacking enthusiast, join in the discussion! Perfect place for someone looking to get into crypto security, and white-hat hackers are always welcome.