Unhackable Blockchain? Not anymore!
Since early 2017, hackers have stolen crypto currencies worth nearly $2 billion. This attacks one of the core arguments for the blockchain technology, namely its alleged security. The assertions that blockchains are absolutely secure and cannot be manipulated prove to be simply wrong.
One possibility to hack a blockchain is to take over the majority of the mining power. Thereby the same crypto currency can be used several times.
This risk is very low with very large crypto currencies, such as Bitcoin, since an immense computer volume is needed to gain 51% of the mining power. Therefore, hacker attacks concentrate on smaller block chains. The smaller the blockchain, the easier an attack becomes.
How and whether these security gaps within the blockchain technology will be solved remains to be seen.