whysosadge

Depending on the use case. Symmetric crypto varies. For example, if your source only has 100 bits of classical entropy. For example, fuzzy extractors.

It becomes manageable to break it now with a QC.

I’m exaggerating a lot here, but one concern people have with quantum computing is what if it breaks all cryptography, but doesn’t help us solve “useful” problems.

The what if is pulling a lot of weight here but I hope it makes my point.