Re:A Graduate Course in Applied Cryptography
by archgoon on Friday January 10, 2020 @10:45PM
(#22017984)
> Microprocessors reached that high MOS transistor count less than 10 years ago.
Note however that quantum computers can potentially benefit from existing lithography processes, so it may not take as long to scale up as we have already developed processes for very small highly integrated circuits.
Re:A Graduate Course in Applied Cryptography
by adtac on Saturday January 11, 2020 @04:45AM
(#22019104)
We don't need quantum computers to be at microprocessor scale to make 2048-bit RSA factoring groundbreaking. If a quantum computer the size of a car can do it in 8 hours, it's sufficient.
Article "How to factor 2048 bit RSA integers in 8 hours using 20 million noisy qubits" https://arxiv.org/abs/1905.09749 shows how to significantly reduce the cost of factoring integers and computing discrete logarithms. Implementation of the efficient device mentioned in the article requires 2.7 billion Toffoli gates for 2048 bit input. It could factor one key in 8 hours.
Microprocessors reached that high MOS transistor count less than 10 years ago. For example, 8-core Core i7 Haswell-E has 2.6 billion transistors (2014). If quantum computers follow Moore's law like conventional IC, it will take 40-years before they can factor 2048 bit RSA.