Halborn discovered a massive #ZeroDay vulnerability code-named Rab13s impacting Dogecoin and 280+ networks, including Litecoin and Zcash, putting over $25 Billion of digital assets at risk. To understand the zero-day vulnerability Rab13s, we need to go through some basic concepts. So I would like to explain blockchain and its key characteristics. Blockchain is a data structure used to represent a cryptocurrency. Stores data in a way that allows multiple parties to access it reliably without having to trust one another.