51% Attack: What It Is, How It Works, and Why It Matters in Crypto

When someone controls more than half of a blockchain’s mining power, they can pull off a 51% attack, a scenario where a single entity or group gains majority control over a blockchain’s network to manipulate transactions. Also known as a majority attack, this isn’t science fiction—it’s a real threat that’s happened before, and it’s why some blockchains are safer than others.

Here’s how it works: blockchains rely on miners or validators to confirm transactions and add new blocks. If one person or group controls over 50% of the total computing power (hash rate), they can outpace everyone else. That means they can reverse their own transactions—called double spending, the act of spending the same cryptocurrency twice by rewriting transaction history—block popular exchanges, or stop new transactions from confirming. It doesn’t let them steal coins directly, but it breaks trust in the system. And once trust is gone, the coin’s value drops fast. This is why smaller blockchains with low hash rates, like some altcoins listed in our posts, are far more vulnerable than Bitcoin or Ethereum.

The consensus mechanism, the system that ensures all participants agree on the state of the blockchain plays a big role here. Proof-of-Work chains like Bitcoin are harder to attack because they need massive, expensive hardware. But Proof-of-Stake chains? They use different rules, and a 51% attack there would mean owning over half the staked tokens—which is often even harder. Still, some projects skip security checks to save costs, making them easy targets. You’ll see this in posts about exchanges like OrangeX and Bitwired, where weak infrastructure or low liquidity makes tokens ripe for manipulation. Even something as simple as a low-volume token swap, like BNX to FORM, can be exploited if the network isn’t properly secured.

Real-world examples? In 2018, Ethereum Classic suffered a 51% attack that reversed over $15 million in transactions. Smaller chains like Verge and Bitcoin Gold have been hit too. These aren’t theoretical risks—they’re warnings. If you’re holding a coin with no major exchange support, low trading volume, or no clear mining distribution, you’re playing with fire. The posts below dive into exactly these kinds of risky assets—from dead meme coins like Cony and QSTaR to unregulated exchanges that lack basic security. You’ll find out which coins are safe, which are scams, and how to spot a blockchain that’s just one bad actor away from collapse. Stay sharp. Your funds depend on it.