[Cryptography] quantum computers & crypto

[Ray Dillinger]

On 10/31/21 7:54 AM, Peter Gutmann wrote:
> Ray Dillinger <bear at sonic.net> writes:
>
>> All software with symmetric keys upgraded to handle keys twice as long so
>> symmetric crypto can be secure in a post-QC world?  Harmless.
> Cost of replacing the entire global infrastructure that we've spent forty odd
> years building with non-PQ crypto?  Boundless.
>
> Peter.
>
>
Does that global infrastructure truly depend on those keys being short?

If so we learned nothing from the DES debacle.

Does that global infrastructure truly depend on them having fixed length?

If so we learned nothing from "640k ought to be enough for anybody" and
besides we aren't allowing for IVs and composable keys.

So where fixing those things has a significant cost, that cost is a sign
that they needed fixed anyway.

            Bear