# What is quantum computing?
When we talk about quantum computing we refer to a field of computing where the mathematical and logical theory of its operation is transferred to the atomic world. That is, it is an application of quantum mechanics in computation theories, to allow us to use the power of the atom and its states, to create extremely efficient computer equipment and algorithms based on the principles of uncertainty, probability, and quantum states of the systems.
It is a huge evolution of traditional computing. One where we use circuits and logic gates to create teams. This together with binary programming and logical-mathematical rules that have been with us for a long time. Instead, we replace this with atoms in different states of energetic excitation, representing different informational states at the same time.
Thus we could define that a quantum computer is a computer that uses qubits to perform operations instead of the traditional bits of classical computers. This seemingly small difference is what allows quantum computers to gain enormous computational power. Even the ability to solve problems that a normal computer could never solve.
# Benefits and dangers
Now, the emergence of quantum computing certainly allows us to achieve a number of impressive benefits. And how could it be otherwise, it also contains many dangers
In general, the main benefits of quantum computing come from an improvement in our technology. We spoke that we would be able to make enormous advances in areas such as computer security, medicine, economics, artificial intelligence, economics, materials design, and scientific research in different fields. Without a doubt, it would be an era of a great amount of new knowledge that we as a species can reach.
However, it also carries enormous dangers. With a quantum computer, for example, our current cryptography systems could quickly break down. This would make hacking secure computer systems something very simple, not only that, whoever has a quantum computer to spy on us could do it without a problem, breaking the asymmetric encryption of our communications would not require much effort.
Of course, we could make quantum cryptography systems that would be our line of defense. But making quantum computing mainstream will take a long time, at least 50 more years of work and research. Given this perspective, whoever manages to obtain the first general-purpose quantum computer will have potential in their hands capable of putting the world's cybersecurity in check. Something that means a huge risk for everyone, and that especially puts cryptocurrencies at a delicate point.
# Quantum computing and cryptocurrencies
Now, what danger does quantum computing mean for cryptocurrencies? As we've mentioned, quantum computing has the potential to break asymmetric cryptography. This means that each and every one of the blockchains and cryptocurrencies that we know of are at risk.
Of course, this does not mean that cryptocurrency projects are unaware of this and have taken action to correct it. A good example of this is the myth that Bitcoin will come to an end when quantum supremacy (the ability to create high-capacity quantum computers) is achieved.
This myth is based on the fact that ECDSA and SHA-256 could be broken with this method. As in all myths, there is some truth and a lot of misinformation. For example, to break ECDSA we need a quantum computer with a capacity of about 1500 qubits, something that we are still a long way from. In fact, the most powerful system we have right now is only 54 qubits, in the hands of Google. This debunks that we are in imminent danger.
Second, in Bitcoin, the creation of P2PKH (Pay To Public Key Hash) type transactions adds an additional security measure to protect public keys from a possible attack of this type. By applying a SHA-256 and RIPEMD-160 hash on the public keys, we managed to obfuscate the key to prevent them from being attacked directly. It is certainly not a top-notch security measure, but it effectively makes it difficult for a quantum computer to break the public key and obtain the private key and thus gain control over our cryptocurrencies.