On July 10, 2018, news broke that cryptocurrency wallet and decentralized exchange Bancor was hit with a hack. A wallet the Bancor team used to update the protocol’s smart contracts was infiltrated, and the $23.5 million vulnerability allowed the hackers to run off with $12.5 million ETH, $1 million NPXS tokens and $10 million of Bancor’s BNT token.Following the hack, the Bancor team froze the BNT in question in an effort to stanch its losses.The latest of its kind, the attack is an unfortunate reminder that smart contracts are not foolproof. Even built as they are on the blockchain’s security intensive network, they can feature bugs, backdoors and vulnerabilities that are ripe for exploitation. Before Bancor, we saw the popular Ethereum wallet Parity drained of 150,000 ETH (now worth just over $68 million) in July of 2017. In November of the same year, Parity lost even more than this when a less-experienced coder accidentally froze some $153 million worth of ether and other tokens.In perhaps the most infamous smart contract hack in the industry to date, The DAO, a decentralized venture fund, lost 3.6 million ether in June of 2016. The stolen funds are now worth $1.6 billion, and the fallout of the attack saw Ethereum hard fork to recoup losses.The Why and How: Making the Same Mistake If three’s company, then The DAO, Parity and now Bancor have become the poster triplets of smart contract vulnerabilitie...
