Systems, apparatuses, methods, and computer program products are disclosed for PQC. An example method includes transmitting a first portion of an electronic communication to a client device over a non-PQC communications channel, wherein the client device comprises a PQC shim circuitry. The example method further includes transmitting one or more communications between a PQC callback circuitry and the client device over a PQC communications channel, wherein the client device is a non-PQC device. The example method further includes transmitting a second portion of the electronic communication to the client device over a PQC communications channel.