To date the only practical replacements for RSA and EC achieve key derivation but not signatures. Without signatures we're not really 'complete' since certifica

To date the only practical replacements for RSA and EC achieve key derivation but not signatures. Without signatures we're not really 'complete' since certificates are hard to do with only key derivation. Post-quantum cryptograph research is a very active area right now. If these researchers do not find a practical signature algorithm, PKI as we know it will change very significantly. Ironically, blockchains might elevate in importance as a result, since the evolving blockchain is a useful construct for quantum resistance. It has cryptographic agility built in.