Old standards like RSA and ECDSA re based on the presumed classical hardness of the discrete log / hiddden subgroup problem, which is known to be quantum easy. New ones are based on lattice shortest vector problems, which are presumed to be both classical and quantum hard. But there's a risk that they turn out to be easy for both.
Is there support in the standards for combining the strength of old and new methods, so that successful attacks requires breaking both types of problems?
Is there support in the standards for combining the strength of old and new methods, so that successful attacks requires breaking both types of problems?