Abstract: Deploying quantum cryptographic appliances within brownfield enterprise architectures requires careful integration with existing identity, monitoring, and routing stacks. This paper outlines enterprise topologies, key caching strategies, and compliance frameworks.
Enterprise CISOs cannot overhaul functional networking backbones to accommodate proprietary quantum protocols. The QKD gateway acts as an impedance-matching security bridge, isolating delicate optoelectronic devices into an administrative DMZ while exposing clean, standard ETSI REST interfaces to core routers.
Unlike classical keys which persist in database tables, QKD keys are intrinsically single-use. We implement secure memory enclaves (mlock / zero-on-free) to prevent key material from being swapped to disk, ensuring that used key material is completely erased within nanoseconds of delivery.
The gateway produces cryptographically signed append-only audit ledgers logging every key grant event, client certificate identity, and byte count without exposing key bits, fulfilling strict PCI-DSS, SOC 2, and DORA regulatory auditing mandates.