Satellite networks must establish secure channels that remain safe against large-scale quantum adversaries. Achieving post-quantum security requires post-quantum key exchange. However, most post-quantum cryptographic schemes have larger public key, ciphertext, and signature sizes than classical ones. Over satellite links with high propagation delay and non-negligible loss, larger messages are more likely to exceed the path MTU, causing fragmentation or retransmissions that degrade handshake performance. We empirically compare the handshake performance of two virtual private network protocols: WireGuard and IPsec modified with post-quantum key exchange algorithms under a simulated satellite network. Our experiments quantify the impact of message size on handshake latency and reliability, and provide practical guidance for designing quantum-secure key exchange for satellite systems.
Satellite networks must establish secure channels that remain safe against large-scale quantum adversaries. Achieving post-quantum security requires post-quantum key exchange. However, most post-quantum cryptographic schemes have larger public key, ciphertext, and signature sizes than classical ones. Over satellite links with high propagation delay and non-negligible loss, larger messages are more likely to exceed the path MTU, causing fragmentation or retransmissions that degrade handshake performance. We empirically compare the handshake performance of two virtual private network protocols: WireGuard and IPsec modified with post-quantum key exchange algorithms under a simulated satellite network. Our experiments quantify the impact of message size on handshake latency and reliability, and provide practical guidance for designing quantum-secure key exchange for satellite systems.
With the introduction of post-quantum cryptography (PQC) algorithms, there are ongoing efforts to not only standardize the proposed solutions but also consider integrating them into existing network applications and evaluating their performance. This evaluation is especially critical for security-sensitive applications such as satellite communications, where network limitations such as high packet loss and propagation delay pose unique challenges. In this paper, we consider the integration of PQC with one of the widely used security protocols, namely IPSec, by focusing on its key exchange protocol IKEv2. Specifically, we evaluate how PQ key exchange and digital signatures impact the latency compared to existing classical crypto solutions. We demonstrate through simulation how such integration triggers fragmentation that needs to be handled by IKEv2 and quantify the performance overhead due to packet loss or delaying of such fragments when used under satellite networking applications. The results indicate that while higher packet losses pose significant overheads that may hinder the adoption of PQ-based IPSec solutions, this may be subsidized when propagation delays are much higher in satellite networks.
This paper presents a U.S.-focused design and evaluation of CRYSTALS-Kyber-based encryption protocols tailored for secure satellite-to-ground communications. With the emerging threat posed by quantum computing to traditional public-key cryptography, the integration of post-quantum encryption schemes such as Kyber has become critical for safeguarding space-based assets. The study evaluates the Kyber protocol in simulated orbital conditions, measuring handshake efficiency, encrypted throughput, packet retransmission resilience, CPU and memory consumption, session recovery latency, and scalability. Kyber demonstrated superior performance in reconnection speed, loss recovery, and session scalability compared to RSA and ECC baselines, while maintaining acceptable computational loads for deployment on both ground stations and small satellite platforms. The protocol’s resilience to variable latency and degraded signal environments confirms its suitability for low-Earth orbit (LEO) communication profiles. Results support phased deployment in U.S. aerospace networks, beginning with mission-critical command links. This work contributes new empirical insights into the readiness of post-quantum cryptography for real-world space applications.
Post-quantum cryptographic (PQC) algorithms are being developed to guard against quantum-computing attacks, but their behavior in constrained Internet of Things (IoT) environments remains an important topic of discussion. In this work, we study the impact of deploying PQC protocols in IoT networks using the Open Quantum Safe (liboqs) framework. In particular, key encapsulation and digital signature schemes are evaluated in terms of their computational performance, communication costs, and energy consumption. Our results indicate that although PQC operations can be completed in microseconds using general-purpose processors, substantially larger key and ciphertext sizes introduce significant communication overhead. When mapped to common IoT protocols such as Bluetooth Low Energy (BLE), IEEE 802.15.4 (Zigbee), and LoRa, these larger payloads must be divided into multiple packets. In low-payload LoRa networks, for example, ML-KEM handshakes can require up to 62 packets. This level of fragmentation increases latency and energy consumption, thus potentially affecting reliability. Furthermore, when packet delivery probabilities approaching 99% are achieved, handshake success rates can drop to values approaching 50%. These results suggest that communication metrics, rather than computational performance, pose key challenges to PQC deployment in constrained IoT settings.
The current VPN systems that use Classical Cryptography are becoming increasingly vulnerable to attacks on Quantum Computers. This paper examines the creation and implementation of a Quantum-Safe VPN solution that incorporates Post-Quantum Cryptography (PQC) via the Kyber 512 algorithm. The proposal includes a practical client/server implementation using WireGuard as the tunneling protocol and Tailscale for connectivity with an additional level of protection enabling the use of PQC for key exchange via the liboqs library. Selected performance metrics were determined (latency, handshake duration, CPU utilization, throughput) and compared with those of the Classical VPNs. The findings indicate that while PQC will add extra processing overhead (in particular, the Handshake process), it provides a significantly stable and secure channel for communications. Although throughput was less than with Classical VPNs, and CPU usage was increased, the PQC enabled VPN was found to provide acceptable reliability and produce zero packet losses. The results of this study have proven that integration of PQC in a VPN is achievable in real world applications and demonstrates the necessity for secure methods in future networking.
The threat of quantum computers breaking classical cryptographic is accelerating the adoption of quantum- resistant cryptographic algorithms. Several government agencies have set a tight time-line for upgradation of all system to support post quantum cryptographs. We study post-quantum migration of IPSec protocols and their impact on network performance. The large key lengths in Post-Quantum Cryptography (PQC) cannot fit in a single IP packet leading to IP fragmentation. This can cause failure of security associations and degrade performance of IKEv2 under poor network conditions. To tackle this problem, we study a new key- sharing mechanism for IKEv2 and evaluate its performance. Unlike current hybrid key-sharing approaches, which send the classical and quantum keys sequentially over UDP or TCP (as in RFC 9370), the new approach concatenates them into a single composite key and transport them over TCP to ensure a reliable handshake. We implement and benchmark the new composite key-sharing handshake mechanism against existing hybrid algorithms that use either UDP or TCP. Extensive experiments under various network conditions demonstrate that the new approach significantly improves handshake time and energy consumption by avoiding the severe retransmission penalties of the Hybrid handshake mechanism. At 1% packet loss, the handshake time of composite key sharing mechanism is better by atleast 20% than hybrid mechanisms, and the improve- ment get better with higher packet loss reaching 30% at 10% packet loss. Energy consumption follows the same pattern achieving reduction of 29% at 10% packet loss
WireGuard's handshake relies on a static-static Diffie-Hellman operation for which no practical post-quantum analogue exists. PQ-WireGuard addresses this limitation by restructuring the handshake around key encapsulation mechanisms (KEMs) and leveraging WireGuard's assumption that peers' static public keys are distributed out of band. This approach keeps the handshake within a single unfragmented datagram despite large post-quantum public keys while preserving initiation-message authentication. However, these assumptions break down in mesh and peer-to-peer deployments, where peers are discovered dynamically, static public keys are public by design, and the resulting default pre-shared key is computable by any observer. As a result, deployed post-quantum VPNs disable mesh networking when post-quantum mode is enabled. This paper characterizes the problem as a fundamental trade-off between KEM selection, key distribution, and wire image, and presents PQ-MESH, a post-quantum key establishment protocol for dynamically discovered peers that provides confidentiality and authentication without a coordination server. PQ-MESH carries lattice-based static public keys inline, protects responder resources using a stateless address-validation token before fragment reassembly, and binds KEM and signature keys into a single node identity. We describe the protocol, provide a reference implementation, and evaluate its wire overhead. Our evaluation shows that carrying a complete peer identity inline requires 1,312 bytes and expands the initiation flight to 7,296 bytes over seven datagrams at a 1,200-byte MTU. Despite this larger wire image, responder cost before authentication remains bounded to 54 transmitted bytes, zero allocated state, and no public-key operations, yielding an amplification factor of 0.0450. We also report a negative result: supporting mesh networking necessarily moves the handshake away from the two-datagram post-quantum QUIC Initial profile rather than toward it. This work presents a protocol design, specification, and reference implementation. It does not include a mechanized formal security proof, traffic-classification analysis, or evaluation over real network paths.