I want to talk about this for years. I want to show people what are the systematic risk bitcoin has and I believe everyone should know it. I’m a very early bitcoin adopter. I bought buy first bitcoins in 2013 where the prices are around 10-25 bucks. As a mathematician, I want to share the concerns I have to everyone here.
For those that understand Markov chain and basic probability theory, you could just go see my youtube video which shows you how blockchain’s double spending is modelled using Markov chain and what is the systematic risk: [https://youtu.be/l-rRwSZEkLE](https://youtu.be/l-rRwSZEkLE)
Bitcoin and blockchain in general is safe. But there is potential risk. That is double spending. Satoshi’s paper shows you that such risk decreases exponentially, however, the pooled mining gives attackers the ability to hijiack the main chain (which I explained mathematically in my video). Moreover, such risk is not low at all. **If an attacker obtains 40% of the hashing power in the entire network, he will have a 44% chance to reverse his previous transaction!** And there’s no way to solve it. Blockchain is great but it’s not perfect. I hope more people knows about it. We shouldn’t stop here, blockchain is just the beginning of decentralized cryptocurrency, we need more innovation, not just blockchain.