You should read the paper authors' paper directly; a preprint version if available on arXiv.[1]
The authors don't provide a complexity analysis of their algorithm; in lieu of attempting to derive that analysis myself, I'm deeply skeptical that their algorithm can find arbitrarily large prime numbers in sub-exponential time; let alone the polynomial time needed for breaking classical public-key cryptography. The absence of such a complexity analysis is conspicuous because such an analysis would be groundbreaking.
However, I don't need to lean on the conspicuous absence of a proof of polynomial time complexity for their algorithm because their algorithm has explicit limitations. It's an approximation method (albeit with high accuracy) that can only find primes located in dyadic intervals having many Braggs peaks and a relatively small left endpoint. In the paper they represent this interval with (M, M + L); in general a dyadic interval is an interval of the form (k/2n, k+1/2n) which may be either open or closed.
In other words the algorithm has costly limitations, no proof of polynomial time complexity and the authors don't even study its behavior for a left endpoint greater than 10^6. RSA semiprime numbers have 600 digits - this result isn't even in the same galaxy. Considering the explicit limitations in the authors' paper and the lack of interesting analysis indicating otherwise, it's likely that the problem of finding a suitable dyadic interval containing a large semiprime number's factors will just reduce to the problem of finding its factors anyway.
For what it's worth, this is all distinct from a more conceptual problem that undermines any use this result could have for cryptanalysis. Take a look at the prime counting function.[2] Per the prime counting function, there are approximately 2.53274 × 10^305 primes and 2.27654 × 10^613 primes less than 2^1024 and 2^2048, respectively. It's physically impossible to construct a lookup table consisting of all products of all pairs of primes in either set because there isn't enough matter in the universe to contain the information. But even if there was, you would never feasibly pick out the correct semiprime number corresponding to a given RSA private key by doing lookups in this way.
The authors don't provide a complexity analysis of their algorithm; in lieu of attempting to derive that analysis myself, I'm deeply skeptical that their algorithm can find arbitrarily large prime numbers in sub-exponential time; let alone the polynomial time needed for breaking classical public-key cryptography. The absence of such a complexity analysis is conspicuous because such an analysis would be groundbreaking.
However, I don't need to lean on the conspicuous absence of a proof of polynomial time complexity for their algorithm because their algorithm has explicit limitations. It's an approximation method (albeit with high accuracy) that can only find primes located in dyadic intervals having many Braggs peaks and a relatively small left endpoint. In the paper they represent this interval with (M, M + L); in general a dyadic interval is an interval of the form (k/2n, k+1/2n) which may be either open or closed.
In other words the algorithm has costly limitations, no proof of polynomial time complexity and the authors don't even study its behavior for a left endpoint greater than 10^6. RSA semiprime numbers have 600 digits - this result isn't even in the same galaxy. Considering the explicit limitations in the authors' paper and the lack of interesting analysis indicating otherwise, it's likely that the problem of finding a suitable dyadic interval containing a large semiprime number's factors will just reduce to the problem of finding its factors anyway.
For what it's worth, this is all distinct from a more conceptual problem that undermines any use this result could have for cryptanalysis. Take a look at the prime counting function.[2] Per the prime counting function, there are approximately 2.53274 × 10^305 primes and 2.27654 × 10^613 primes less than 2^1024 and 2^2048, respectively. It's physically impossible to construct a lookup table consisting of all products of all pairs of primes in either set because there isn't enough matter in the universe to contain the information. But even if there was, you would never feasibly pick out the correct semiprime number corresponding to a given RSA private key by doing lookups in this way.
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1. https://arxiv.org/pdf/1802.10498.pdf
2. https://en.wikipedia.org/wiki/Prime-counting_function