What are alternatives to number theory based crypto? Quantum crypto,lattice based crypto, Neurocryptography and cellular automata based cryptography are alternatives to number theory based crypto. I need to know what are the other hard problems like Lattice problems and Number theory based problems that can be used for cryptography(For asymmetric crypto).
Code based cryptography like McEliece cryptosystem, is based on the hard problem of decoding linear codes. But i think it lies to the group of quantum based crypto since as far as we know it is still immune to quantum attacks