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The 51% Attacks That Hit Bitcoin Gold and Verge

The 51% Attacks That Hit Bitcoin Gold and Verge

Blockchain was supposed to be trustless, immutable, and secure. But then came a pair of painful reminders that even decentralized networks have weaknesses, especially when the math doesn’t hold up. In May 2018, both Bitcoin Gold and Verge were hit by 51% attacks, shaking user confidence and spotlighting the ongoing arms race between crypto security and malicious actors.

Let’s examine what happened, what it means, and (most importantly) how to avoid becoming collateral damage when someone decides to rewrite the blockchain for profit.

Bitcoin Gold

The attack on Bitcoin Gold (BTG) started quietly. Over the course of a few days, an attacker gained majority control of the network’s hash power. With that power came the ability to validate their own version of transaction history. And that’s exactly what they did.

The attacker began sending large amounts of BTG to exchanges, withdrawing fiat or other coins, and then reversing the original transactions by rewriting the chain. This classic double-spend attack reportedly siphoned off 388,200 BTG, worth around $18.6 million at the time.

In some cases, they managed to roll back transactions up to 22 blocks deep. That’s not a minor blip. It’s a structural flaw being ruthlessly exploited. Some exchanges responded by increasing confirmation thresholds to 50 blocks. For a coin that was once marketed as a “more accessible” version of Bitcoin, this was a brutal blow.

Verge

While Bitcoin Gold was under siege, Verge was dealing with its own crisis. Unlike BTG, Verge’s attacker didn’t need a full 51% of the network. Due to a quirk in how Verge handled timestamps and difficulty adjustments, they were able to slash the mining difficulty by over 99%. Just by spamming the network with blocks.

That let them mine huge numbers of Verge (XVG) with little resistance, essentially printing money. Making matters worse, Verge’s five-algorithm system allowed the attacker to focus on just one (scrypt), meaning they only needed to control about 10% of the total hash power.

Despite community claims that it was “just a DDoS,” the exploit was real and profitable. And this wasn’t even the first time. Verge had already suffered a similar attack just weeks earlier.

Not All Blockchains Are Built Alike

These incidents highlight an uncomfortable truth: not every coin is ready for prime time.

The security of a blockchain doesn’t come from marketing or a whitepaper. It comes from code, decentralization, and hash power. Coins with weak consensus models or small mining communities are inherently more vulnerable. If it’s cheap to attack a chain, someone will eventually try.

But it’s not about choosing “stronger” coins. It’s about how you handle risk.

10 Practical Tips to Stay Safe in an Unsafe Market

Here’s how to protect yourself from being caught in the fallout of poorly secured crypto networks:

  1. Stick to battle-tested blockchains: Bitcoin and Ethereum aren’t perfect, but they’ve proven resilient over time. Smaller chains might offer excitement, but they often lack the security budget to resist attacks.
  2. Watch the hashrate: Low hashrates are a red flag. They mean the network is easier to overpower. Public data on hash rates is widely available; don’t ignore it.
  3. Don’t chase every fork: Bitcoin Gold was born from a hard fork of Bitcoin. Not every fork inherits Bitcoin’s strengths. Ask yourself: what’s the dev team like? Who’s maintaining the network?
  4. Use exchanges with strict confirmation policies: Platforms that require 20, 50, or more block confirmations help protect you from double-spend scams.
  5. Withdraw quickly after trades: Leaving large amounts on exchanges during volatile periods increases exposure to potential chain rollbacks or security breaches.
  6. Stay informed about network health: Community forums, GitHub repos, and crypto Twitter often surface issues before they hit headlines. Know what’s going on with the projects you invest in.
  7. Diversify: Don’t keep your entire portfolio on one chain, especially not a niche one with limited security infrastructure.
  8. Be skeptical of low-cost miracles: If a coin promises fast transactions and zero fees with no visible mechanism to prevent spam or manipulation, that’s a risk, not a feature.
  9. Evaluate validator or miner incentives: A secure network pays enough to keep honest actors involved. If mining isn’t profitable, the system is likely unstable.
  10. Use hardware wallets and full nodes where possible: These tools help verify transactions independently and reduce reliance on centralized infrastructure that could be compromised.

Security Is the Real Utility

There’s a lesson in every breach. For all the talk about innovation and scalability, the fundamental utility of any blockchain is this: it works as intended, and nobody can cheat it.

Bitcoin Gold and Verge forgot that rule, or failed to enforce it. And users paid the price.

If we’re going to build a financial system that doesn’t rely on trust, then the code must be worthy of that trust. Otherwise, decentralization is another buzzword. Until the next 51% attack shows up to remind everyone what’s at stake.