Threats to bitcoin (1) — Quantum Computing
I have talked about many advantages of using bitcoin. Perhaps you have already fallen in love with it. Yet, we, as a critical thinker, need to ask a very important question. Is bitcoin perfect? Of course not! Nothing is perfect even for your girlfriend or boyfriend. (No offence 😊) The potential threats to bitcoin can be classified into four main categories, i.e. core technology, performance, operation and legitimacy.
Let’s talk about core technology first. Bitcoin is a cryptocurrency based on cryptography. Owning bitcoin means the ownership of a private key and a transaction record stored in the blockchain specifying the associated bitcoin address as a recipient. Users can spend and receive bitcoin by presenting private key and bitcoin address respectively. Therefore, anyone can spend other people’s bitcoin if they know their private keys. The bitcoin address is generated from private key by using cryptography functions called Elliptic curve point multiplication and hashing algorithm. It is very easy to compute bitcoin address by knowing private key while it is almost infeasible to calculate the private key by knowing bitcoin address. It takes the most powerful supercomputer network nearly 10¹⁸ years to crack the private key. However, the rise of quantum computing may be a threat to the bitcoin cryptography as the quantum computer possess much stronger computational power than a traditional computer which can crack the private key within a reasonable amount of time.
Does it mean the end of bitcoin? Fortunately, cryptographers have foreseen this problem since 2006 and have developed some post-quantum cryptographic algorithms. You may be confused by the year 2006 which is earlier than the creation of bitcoin. How come? In fact, cryptography is widely used in many industries. For example, government use cryptographic algorithms to encrypt sensitive documents. There will be adverse effects far beyond bitcoin for the breakdown of cryptography. Experts in different industries and cryptographers will soon come up with a new standard which is resistant to quantum computing attack. As long as the bitcoin community agrees to upgrade the existing cryptography before the mass adoption of quantum computing, our bitcoin will be safe in the future.
