you may want to have a look at sphincs. its security is based on hash-functions, therefore unlike most other postquantum schemes it can be considered very relia

you may want to have a look at sphincs. its security is based on hash-functions, therefore unlike most other postquantum schemes it can be considered very reliable (good hash functions are a solved problem these days). Downside: signatures are big (~40k). For TLS this is unworkable, for a PGP-like system this is doable. https://sphincs.cr.yp.to/ https://sphincs.cr.yp.to/