A Post-Quantum Secure Multi-Tenant Cloud Architecture with Scalable Key Management and Side-Channel Resistance

Abstract

To meet the performance and scalability demands of current cloud systems, cryptographic systems should be resistant to both quantum and classical adversaries, especially considering the future potential provided by quantum computing. The presented manuscript provides an integrated, quantum-resistant, cloud-based encryption architecture built on the combination of post-quantum authentication, scalable, multi-tenant, key-management methods, and side-channel-conscious design in a cloud-native paradigm. The lattice-based post-quantum key-encapsulation scheme to derive the long-lived and tenant-specific cryptographic key is built into the system to remove all possible single-point failure sources. Long-lived and tenant-specific cryptographic keys are subsequently replicated in a threshold-based key-management service (KMS) cluster. Lightweight symmetric primitives are used to compute session keys thus reducing client-side latency on resource-constrained devices. The AES -256-GCM or Ascon encryption schemes are deployed to guarantee confidentiality of data. Moreover, the architecture uses the symmetric message authentication codes and lattice-signature schemes produced using quantum-safe primitives to ensure the data integrity and authenticity. By distributing key computations across isolated KMS nodes and restricting direct use of long-lived secrets to bounded and infrequent operations, the implementation utilizes leakage-resilient techniques. The system, which is designed for elastic scalability, provides fine-grained access control through configurable lattice-based attribute-based encryption and dynamically allocates keys for new tenants. Experimental benchmarks show that the technique attains strong multi-tenant isolation and side-channel information leakage resistance while minimizing handshake latency by considerable amounts over per-session post-quantum exchanges. This model surmounts the shortcomings of current post-quantum, multi-tenant, and cloud-native security systems by integrating quantum-resistant cryptographical principles, distributed mechanisms for trust, and lightweight operational techniques and thus offers a practical and flexible solution for secure protection of sensitive cloud-hosted data in the future quantum era.