Quantum computing threatens current public-key cryptography. New quantum-safe communication protocols are needed to address this threat. PQConnect is a tunnelling protocol designed for automated, end-to-end secure communication that resists quantum attacks while remaining compatible with existing infrastructure. It employs a hybrid handshake integrating classical and post-quantum primitives to establish shared keys. This thesis analyses PQConnect’s handshake, which uses a nested hybrid key exchange combining three schemes. It layers Classic McEliece (a code-based key encapsulation), X25519 (Curve25519 elliptic-curve Diffie–Hellman), and SNTRUP761 (Streamlined NTRU Prime) key encapsulations. These are being utilized as Key Encapsulation Mechanisms (KEMs). The layers are nested so that each inner exchange is concealed by outer layers, making any single layer difficult to break. The analysis details how each layer contributes to key establishment and how fresh ephemeral keys ensure forward secrecy. Additional PQConnect mechanisms are examined, including streaming verification of hand-shake data and DNS-based key distribution. Streaming verification processes large hand-shake records incrementally, reducing memory usage. For key distribution, PQConnect retrieves hashed server public keys via authenticated DNS records: a client fetches a hash of the server’s long-term key from DNS and verifies it before initiating the handshake, avoiding reliance on centralized certificates. A ratcheting key schedule derives new chain keys for each time epoch and per-packet encryption keys, limiting key exposure and extending forward secrecy beyond the initial handshake. For performance evaluation, packet-level traffic was captured using Wireshark for both PQConnect and traditional TLS sessions. Captured packets were analyzed to compare handshake flows and performance metrics such as packet size and total transmitted data. The results show that PQConnect introduces only a modest increase in packet sizes and overall data volume, with no significant latency overhead. Streaming verification and DNS-based lookup were confirmed to function correctly without noticeable delay. In conclusion, the study finds that PQConnect can establish quantum-secure tunnels with minimal performance penalty. Its hybrid handshake effectively integrates post-quantum primitives while maintaining compatibility with current infrastructure. DNS-based key distribution and streaming verification enhance trust and efficiency. The ratchet mechanism provides robust forward secrecy. These findings suggest that PQConnect is a practical and future-ready solution for secure tunnelling.
Quantum computing threatens current public-key cryptography. New quantum-safe communication protocols are needed to address this threat. PQConnect is a tunnelling protocol designed for automated, end-to-end secure communication that resists quantum attacks while remaining compatible with existing infrastructure. It employs a hybrid handshake integrating classical and post-quantum primitives to establish shared keys. This thesis analyses PQConnect’s handshake, which uses a nested hybrid key exchange combining three schemes. It layers Classic McEliece (a code-based key encapsulation), X25519 (Curve25519 elliptic-curve Diffie–Hellman), and SNTRUP761 (Streamlined NTRU Prime) key encapsulations. These are being utilized as Key Encapsulation Mechanisms (KEMs). The layers are nested so that each inner exchange is concealed by outer layers, making any single layer difficult to break. The analysis details how each layer contributes to key establishment and how fresh ephemeral keys ensure forward secrecy. Additional PQConnect mechanisms are examined, including streaming verification of hand-shake data and DNS-based key distribution. Streaming verification processes large hand-shake records incrementally, reducing memory usage. For key distribution, PQConnect retrieves hashed server public keys via authenticated DNS records: a client fetches a hash of the server’s long-term key from DNS and verifies it before initiating the handshake, avoiding reliance on centralized certificates. A ratcheting key schedule derives new chain keys for each time epoch and per-packet encryption keys, limiting key exposure and extending forward secrecy beyond the initial handshake. For performance evaluation, packet-level traffic was captured using Wireshark for both PQConnect and traditional TLS sessions. Captured packets were analyzed to compare handshake flows and performance metrics such as packet size and total transmitted data. The results show that PQConnect introduces only a modest increase in packet sizes and overall data volume, with no significant latency overhead. Streaming verification and DNS-based lookup were confirmed to function correctly without noticeable delay. In conclusion, the study finds that PQConnect can establish quantum-secure tunnels with minimal performance penalty. Its hybrid handshake effectively integrates post-quantum primitives while maintaining compatibility with current infrastructure. DNS-based key distribution and streaming verification enhance trust and efficiency. The ratchet mechanism provides robust forward secrecy. These findings suggest that PQConnect is a practical and future-ready solution for secure tunnelling.
This paper introduces PQConnect, a post-quantum end-to-end tunneling protocol that automatically protects all packets between clients that have installed PQConnect and servers that have installed and configured PQConnect.Like VPNs, PQConnect does not require any changes to higher-level protocols and application software.PQConnect adds cryptographic protection to unencrypted applications, works in concert with existing pre-quantum applications to add postquantum protection, and adds a second application-independent layer of defense to any applications that have begun to incorporate application-specific post-quantum protection.Unlike VPNs, PQConnect automatically creates end-to-end tunnels to any number of servers using automatic peer discovery, with no need for the client administrator to configure perserver information.Each server carries out a client-independent configuration step to publish an announcement that the server's name accepts PQConnect connections.Any PQConnect client connecting to that name efficiently finds this announcement, automatically establishes a post-quantum point-to-point IP tunnel to the server, and routes traffic for that name through that tunnel.The foundation of security in PQConnect is the server's longterm public key used to encrypt and authenticate all PQConnect packets.PQConnect makes a conservative choice of postquantum KEM for this public key.PQConnect also uses a smaller post-quantum KEM for forward secrecy, and elliptic curves to ensure pre-quantum security even in case of security failures in KEM design or KEM software.Security of the handshake component of PQConnect has been symbolically proven using Tamarin.
The emergence of quantum computing presents a significant threat to classical cryptographic primitives, particularly those employed in securing internet communications via widely used protocols such as Transport Layer Security (TLS). As conventional key exchange mechanisms will become increasingly vulnerable in the post-quantum era, the integration of post-quantum cryptographic (PQC) algorithms into existing security protocols is of utmost importance. This study investigates the impact of incorporating PQC key encapsulation mechanisms—specifically, the recent standards CRYSTALS-Kyber and HQC, in conjunction with the candidate standard BIKE—into the TLS 1.3 handshake. A comprehensive experimental evaluation was conducted to measure handshake latency under emulated network conditions with varying packet loss probabilities. The findings offer useful insights into the performance trade-offs introduced by PQC integration and further highlight the necessity of a timely transition to post-quantum cryptographic standards.
The advancement of quantum computing creates a big threat to classical cryptographic protocols, including TLS, which is responsible for secure internet communications. While recent industry and academic efforts have focused on integrating lattice-based post-quantum key encapsulation mechanisms (KEMs) such as Kyber+X25519 into hybrid TLS handshakes, these approaches often prioritize performance at the cost of cryptanalytic diversity. Code-based KEMs, despite their proven security measure they remain underexplored in hybrid frameworks due to some limitations like large key sizes and integration complexity. This paper proposes a novel hybrid TLS framework that explicitly incorporates code-based post-quantum cryptography—specifically McEliece—alongside classical key exchange mechanisms. The framework introduces a dual-handshake mechanism, adaptive parameter selection, and seamless fallback negotiation, enabling flexible deployment across heterogeneous networks while ensuring backward compatibility. Integration with Quantum Random Number Generators (QRNGs) and multifactor authentication further increases entropy quality and session security. We implemented and evaluated the framework using an OpenSSL-OQS integration. We measure handshake latency, CPU utilization, memory usage, and throughput across emulated and real-world testbeds. Results show that the proposed hybrid approach achieves up to 30% lower latency and significantly reduced resource overhead compared to pure post-quantum TLS variants, while maintaining near-classical efficiency levels. Mathematical modeling formalizes these trade-offs which offers a foundation for optimizing deployment in both resource-constrained IoT devices and high-performance servers. By advancing cryptographic diversity and aligning with emerging NIST and IETF standardization efforts, the proposed framework provides a practical pathway toward quantum-resilient secure communication.It shows that code-based post-quantum cryptography can be added to current TLS systems without any problems, keeping security, performance, and compatibility in mind as we get ready for the quantum age.
The emergence of large-scale quantum computers poses a significant threat to current cryptographic protocols, particularly Transport Layer Security (TLS), which relies on RSA and elliptic curve cryptography vulnerable to Shor's algorithm. This paper presents a hybrid framework for quantum-resistant TLS handshakes that integrates post-quantum cryptography (PQC), quantum key distribution (QKD) and classical cryptography to provide comprehensive protection against both classical and quantum attacks. The approach employs three QKD protocols; BB84, E91, and Measurement-Device-Independent QKD (MDI-QKD) alongside NIST-standardized PQC algorithms as well as alternative candidates such as HQC and BIKE. A key innovation is the QKD key management module, which addresses performance bottlenecks through periodic key generation and secure reuse within predefined retention periods, significantly reducing QKD overhead in TLS handshakes. The experimental implementation using the quantum network simulator evaluated 144 distinct cryptographic protocol combinations. Results demonstrate that ML-KEM combined with ML-DSA provides optimal PQC performance, while QKD protocol selection is distance-dependent: BB84 for short-range and MDI-QKD for long-distance communication. The framework includes various attack mitigation mechanisms and ensure security as long as at least one cryptographic method remains uncompromised. Consistent with current global quantum network usage, the proposed TLS approach is designed primarily for MAN and WAN environments rather than the Internet, providing a balanced solution that combines theoretical security guarantees with computational efficiency.
Recent advances in quantum computing indicate that several cryptographic mechanisms widely used today may become unreliable in the foreseeable future. In particular, publickey systems based on RSA, elliptic-curve cryptography, and Diffie-Hellman key exchange rely on mathematical assumptions that are known to be vulnerable to quantum algorithms. Even though practical large-scale quantum computers are not yet available, encrypted data exchanged today can be stored and retrospectively decrypted once such machines become feasible, making early migration toward quantum-resilient solutions necessary. This paper presents PQNoise, a post-quantum secure extension of the Noise Protocol Framework implemented in Java. The proposed framework integrates NIST-standardized latticebased primitives, namely CRYSTALS-Kyber for key establishment and CRYSTALS-Dilithium for authentication, while still supporting widely deployed classical algorithms such as X25519 and Ed25519. The system is designed to operate in three modes: classical, post-quantum, and hybrid. In the hybrid configuration, shared session keys are derived by combining secrets from both classical and post-quantum mechanisms using HKDF, thereby providing protection even if one class of primitives is later weakened. In addition to describing the architectural design and protocol integration strategy, this work reports on a detailed experimental evaluation of the proposed system. The results indicate that, although post-quantum and hybrid handshakes introduce additional computational and bandwidth overhead, the overall performance remains within practical limits for realworld deployment. PQNoise therefore offers a realistic and incremental path toward quantum-resilient secure communication systems.
The reliance on asymmetric public key cryptography (PKC) and symmetric encryption for cyber-security in current telecommunication networks is threatened by the emergence of powerful quantum computing technology. This is due to the ability of quantum computers to efficiently solve problems such as factorization or discrete logarithms, which are the basis for classical PKC schemes. Thus, the assumption that communications networks are secure no longer holds true. Quantum Key Distribution (QKD) and post-quantum cryptography (PQC) are the first cyber-security technologies that allow communications to resist the attacks of a quantum computer. To achieve quantum-resistant communications, the aforementioned technologies need to be incorporated into a network security protocol such as Transport Layer Security (TLS). In this paper, we describe and implement two novel, hybrid solutions in which QKD and PQC are combined inside TLS for achieving quantum-resistant authenticated key exchange: Concatenation and Exclusively-OR (XOR). We present the results, in terms of complexity and security enhancement, of integrating state-of-the-art QKD and PQC technologies into a practical, industry-ready TLS implementation. Our findings demonstrate that the adoption of a PQC-only approach enhances the TLS handshake performance by approximately 9 % compared to classical methods. Furthermore, our hybrid PQC-QKD quantum-resistant TLS comes at a performance cost of approximately 117 % during the key establishment process. In return, we substantially augment the security of the handshake, paving the road for the development of future-proof quantum-resistant communication systems based on QKD and PQC.