EP164 Quantum Computing: Understanding the (very serious) Threat and Post-Quantum Cryptography Cloud Security Podcast by Google

Guest:
Jennifer Fernick, Senor Staff Security Engineer and UTL, Google
Topics:
Since one of us (!) doesn't have a PhD in quantum mechanics, could you explain what a quantum computer is and how do we know they are on a credible path towards being real threats to cryptography? How soon do we need to worry about this one?
We’ve heard that quantum computers are more of a threat to asymmetric/public key crypto than symmetric crypto. First off, why? And second, what does this difference mean for defenders?
Why (how) are we sure this is coming? Are we mitigating a threat that is perennially 10 years ahead and then vanishes due to some other broad technology change?
What is a post-quantum algorithm anyway? If we’re baking new key exchange crypto into our systems, how confident are we that we are going to be resistant to both quantum and traditional cryptanalysis? 
Why does NIST think it's time to be doing the PQC thing now? Where is the rest of the industry on this evolution?
How can a person tell the difference here between reality and snakeoil? I think Anton and I both responded to your initial email with a heavy dose of skepticism, and probably more skepticism than it deserved, so you get the rare on-air apology from both of us!
Resources:
Securing tomorrow today: Why Google now protects its internal communications from quantum threats
How Google is preparing for a post-quantum world
NIST PQC standards
PQ Crypto conferences
“Quantum Computation & Quantum Information” by Nielsen & Chuang book
“Quantum Computing Since Democritus” by Scott Aaronson book
EP154 Mike Schiffman: from Blueboxing to LLMs via Network Security at Google