Hybrid QKD and post-quantum cryptography in secure key exchange

The advent of quantum computing poses a significant threat to classical cryptographic systems, necessitating the development of quantum-resistant alternatives. This thesis explores a hybrid key exchange framework combining Quantum Key Distribution (QKD) with Post-Quantum Cryptography (PQC) to secure...

Descripción completa

Detalles Bibliográficos
Autor: Smilenov, Ivan Yavorov
Tipo de recurso: tesis de maestría
Fecha de publicación:2025
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/450784
Acceso en línea:https://hdl.handle.net/2117/450784
Access Level:acceso abierto
Palabra clave:Cryptography
Hybrid systems
QKD
PQC
Quantum
Key distribution
Key exchange
Authentication
Hybrid
Encryption
Criptografia
Sistemes híbrids
Àrees temàtiques de la UPC::Informàtica::Seguretat informàtica::Criptografia
Descripción
Sumario:The advent of quantum computing poses a significant threat to classical cryptographic systems, necessitating the development of quantum-resistant alternatives. This thesis explores a hybrid key exchange framework combining Quantum Key Distribution (QKD) with Post-Quantum Cryptography (PQC) to secure classical post-processing steps such as information reconciliation and privacy amplification. Specifically, CRYSTALS-Kyber is used for key encapsulation, while CRYSTALS-Dilithium and SPHINCS+ provide digital signatures for authentication. While the mathematical security foundations of these algorithms are assumed, their integration is evaluated through performance benchmarking and system-level analysis. The results show that incorporating PQC-based authentication into QKD post-processing significantly improves resilience against quantum adversaries, while introducing only a reasonable computational and bandwidth overhead. This work contributes to the development of robust hybrid cryptographic systems capable of with standing both classical and quantum-era threats.