What is a quantum computer

For a regular computer a bit can be either a 0 or a 1 but a quantum bit can be either a 0 or a 1 or both 0 at the same time this gives it exponentially more power over a conventional computer which would use 8 bits just to store a single number, whereas an 8 qubit quantum computer can store all the numbers between 0 and 256. So if there are 500 qubits then you have more possibilities than there are atoms in the visible universe, wow what this means is that a quantum computer can tackle problems on a scale beyond any conventional computer, from weather prediction and air traffic control to forensics and finance problems and beyond.

Google and NASA has already teamed up to share one of the world's first commercial quantum computers made by Canada's D-Wave, which already been installed and fully operational in a NASA research center in California.

How a Quantum Computer is a threat to Cryptocurrencies

Bitcoin and Ethereum both technologies are based on cryptography that is why they're called crypto currencies and there are two different types of cryptography, symmetric crypto cryptography and asymmetric cryptography for example in a Bitcoin both symmetric and asymmetric cryptography are used.

When someone initiate a transaction then they use their private key and their public key which is used to verify their identity. key infrastructure is actually based on prime numbers and prime factors which are a huge number so if someone wants to hack an SSL encryption or a TLS encryption on the web they would need to find a prime factor which is a gigantic prime number and that is with today technology practically, impossible.

However it will be very possible with quantum computers because with quantum computers we could use an algorithm that is called Shor's algorithm and so with Shor's algorithm the number of steps required to break a private public key encryption will be decreased dramatically, As quantum computer has the ability to go for all the possible outcomes at once.

Cryptography will in deep trouble if quantum computers become so developed that they are able to run Shor's algorithm in an efficient way. Scientific community and the cryptography standards organization which is called equipped standards they say that Bitcoin cryptography will be safe until 2030 or 2040.

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