51% attack over Lisk and Bitcoin Gold over past week

The "unbreakable" blockchain technology is not without flaws. Just over the course of the past 7 days, we have witnessed an attempt to launch the infamous 51% attack on mot only one but two cryptocurrencis - Lisk and Bitcoin Gold.

For Bitcoin Gold, the hacker attempted to double-spend stolen coins from an exchange by exchanging them into fiat currency or another crypto and using the same coins from his or her wallet to buy more crypto. It is estimated that the hacker stole $18 million worth of Bitcoin Gold.

Lisk shared a similar fate, when $550,000 worth of Lisk was lost due to double spending. In this 4 hours long attack attack, the hacker double spent two large transactions (13,000 and 6,600 ZEN) on blocks 318204 and 318234.

There does not appear to be an immediate solution to this issue, as most attackers focus on exchanges,which routinely accept large deposits automatically, and subsequently allow users to trade into different coins and withdraw to another address.

The only comfort the community has so far, is that it would cost any hackers to launch a 51%. The exact cost depends on network complexity and length of attack.

Lets hope the negative sentiment does not spill over to other unaffected cryptos.