Blockchain and quantum computers

Finally, I have been involved into blockchain madness. “Finally” because it seems that hype around blockchain is decreasing and “madness” because I feel like Vavilen Tatarsky from Generation P by Victor Pelevin and Ijon Tichy from The Futurological Congress by Stanislav Lem. And the fact that the project is related to quantum computers adds makes everything more futuristic.

What actually blockchain introduce to our life? Nothing from technical point of view, yes absolutely nothing, just small changes in how digitally signed information is stored and verified and that’s it. But in the social plane, it changes a lot of things, and the funniest, unbelievable and crazy thing is that most of the people involved in the blockchain campaigns can’t predict the impact of the technology and explain why it becomes so popular. I wrote “most” but not “all” here because I still hope that somebody completely understands what we are doing, but I have never seen such person yet:)

But I’m a technical one so let’s return to the ground. And let’s take a look at two modern technologies quantum computers and blockchain. Taking into account that IBM developed their Q System One – the first commercial quantum computer, I would say the quantum computing future is closer than you may thought (https://www.research.ibm.com/ibm-q/system-one/). 

So, why I’m talking about these two technologies? Let’s take a look on any blockchain, Bitcoin for example. It has blocks connected with hash and transactions signed with classic digital signature algorithms with the user’s private key. Actually, this private key with a public part is your cryptocurrency wallet. The most interesting part is that this “classic” signature is vulnerable by quantum computers. Vulnerable means that the private key can be computed by the public key or by any signed data fragment with a quantum computer. Thus the quantum computer can get give you control over any Bitcoin wallet. The good part is that Q System One is not powerful enough for this – only 20 qubits. But it’s clear that one day Bitcoin (and most other blockchains) will become completely unsafe in its’ current implementation and this day is much closer than you may thought.

But as usual, when somebody creates a quantum computer another one creates post-quantum cryptography. So now we are working on a blockchain that is not vulnerable for quantum computer attacks. Sounds like since fiction, doesn’t it? But that is a real customer with a real system. I can disclose all the details now, but I think this year we will have post-quantum blockchain in production.