Some time ago media reports said that if someone can create a quantum computer with more than 4,000 qubits, it will be able to reconstruct (disintegrate) the blockchain. Is that really the case?
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Let's first understand what a quantum computer is.
In simple terms, the quantum computer's operating unit is the qubit instead of the ordinary computer's bits. Ordinary computers can only rely on the 1 or 0 state for data storage; and one has two qubits. The quantum computer can realize the four different valid state values 00, 01, 10 and 11.
This means that each qubit of a quantum computer has much higher computational power than conventional bits. Moreover, the greater the number of qubits, the more obvious the advantage of this speed of operation.
According to Prof. Robert Schoelkopf of Yale University, the 'computer sub-computer has 50 or 100 qubits, and these qubits work well, then you can use this quantum computer as the world's Any ordinary computer will never be able to do the calculations'.
Looking back at the history of quantum computers, in the 1980s, the quantum computer can be said to be more in a state of discourse. Until 1994, when Peter Show presented the quantum-mass factor decomposition algorithm, the quantum computer became Hot topics. And in twenty years later, in 2017, the world’s first quantum computer met with everyone.
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What would anyone think is a threat to the blockchain? The main reason is that its powerful computing capabilities will make the blockchain's security defenses no longer strong.
As you know, Bitcoin's security protocol involves two types of cryptography, namely the hash function (hash function) used in the mining process and the asymmetric cryptography used to provide digital signatures on the blockchain. The future of quantum computers The hash function can be quickly cracked, monopolizing the entire blockchain. There are even predictions that the Shor's algorithm of the 2027 quantum computer can crack keys in ten minutes.
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However, the quantum computer is so terrible? We don't really have to panic too much.
Because of the reality, current quantum computers can achieve up to 72-bit computing power, and the more difficult they are, the more difficult it is to go up. For example, there are fundamental difficulties in implementing quantum computing. Random fluctuations, heat energy of qubits, and even basic The quantum physics process may change the state of the qubits and interfere with it.
While quantum computing is developing, cryptography will inevitably advance with the times. The quantum computer will not be comparable to the existing blockchain cryptography system after 10 years. The so-called quantum hegemony is not easy to implement.