[0xkrt26]

Author here. In the article I explicitly mention that the second part (about high degree polynomial and descrete exponentation) is based on Diffie-Hellman's 1976 paper and presents their one-way function constructions, not MD5 or SHA family (my goal is to cover the history of hashing from the beginning, so I haven't done a research on modern systems yet).

As for the quantum computing stuff, I should have stated more clearly that I'm referring only to quantum computer allowing to calculate descrete logarithms rather fast, and provided a source such as https://math.mit.edu/~shor/elecpubs.html containing a link to the paper Algorithms for quantum computation: Discrete logarithms and factoring by Peter Shor. (I'm planning on covering post-quantum cryptography after I'm done with modern algorithms)