On Passive Permutation Circuits

We present a new way to passively implement permutation circuits, a concept of importance in bit-oriented or line-oriented designs, used in communications, cryptography, field-programmable gate arrays or next-generation pulsed neural networks. We argue that the proposed implementation is more reliable and efficient than previous designs when the number of permuted signals is at least 16. It uses complementary resistive gates, which are natural extensions of the concept of a complementary resistive switch. When Ir/TaO_x/Ta stack is used for switching, the devices show abrupt transitions among a discrete number of states resulting in a complex input-output characteristic. This deviates significantly from the fuzzy logic model of such gates previously proposed on the basis of theoretical models.