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plopiloptoday at 7:31 PM0 repliesview on HN

Y2K devs had it easy, they knew the bug would arrive and when.

The problem with PQC is not that nobody knows when a CRQC (cryptographically relevant quantum computer) will appear, but that by the time it appears, you are already ~10 years too late for migrating (5 years of migration time and 5 years of your adversary silently storing all your classical crypto messages to decrypt them at a later time, the "harvest now decrypt later" attack).

Of course the HNDL attack is only relevant for the most critical pieces of infrastructures, 99% of companies are not a real target for that, especially given the storage cost of such an attack.

There is also the "trust now, forge later" attack, in which a CRQC could break a chain of trust (i.e. digital signatures), and that attack does not need any storage besides the logs of past messages. If you want to guarantee authenticity and unforgeability of your logs for, say, 20 years, you better hope that no CRQC appears by 2050 at least. Once again, it only concerns maybe 1% of companies.

But hey, these 1% companies are exactly the ones that are needing specialised crypto equipment so the move from ANSSI tracks.

I personally do not believe a CRQC will appear before 2050 either. I am willing to bet some money on it, despite researchers in quantum computers being quite confident it will appear in the next 15 years, but I am not willing to bet the entirety of Internet security on it.