Authored by Brandon Black via Bitcoin Magazine,
For as long as Bitcoin has existed, new forms of FUD (fear, uncertainty, and doubt) have been used to predict its demise. Despite this, Bitcoin has grown into a multi-trillion dollar asset and begun to take its place in the global monetary order. In recent months, the specter of a cryptographically relevant quantum computer (CRQC) enabling an attacker to recreate secret keys from public keys and sign Bitcoin transactions moving other people's coins has returned as an evolved form of FUD.
Is this a realistic threat to Bitcoin's continued growth? In a word, no.
There is no evidence that a CRQC will be built within a decade, and it remains unknown whether such a machine will ever be built. The quantum threat remains FUD.
State of the Art
To date, no quantum computing machine has computed anything out of reach of a precocious 6-year-old (confirmed empirically). Quantum computers are remarkable technology and showcase the truly science fiction worthy capabilities of the modern world. These devices harness foundational technologies such as optical tweezers, laser cooling, superconducting flux qubits, electromagnetic traps, dilution refrigerators, and many more. Within these devices individual qubits are coerced into specific subatomic states (different for each candidate technology), entangled into superpositions, manipulated to represent computations, and then their subatomic properties are read and interpreted. The astounding truth is that these devices exist, and can be manipulated
