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The rapid proliferation of resource-constrained IoT devices across sectors like healthcare, industrial automation, and finance introduces major security challenges. Traditional digital signatures, though foundational for authentication, are often infeasible for low-end devices with limited computational, memory, and energy resources. Also, the rise of quantum computing necessitates post-quantum (PQ) secure alternatives. However, NIST-standardized PQ signatures impose substantial overhead, limiting their practicality in energy-sensitive applications such as wearables, where signer-side efficiency is critical. To address these challenges, we present LightQSign (LiteQS), a novel lightweight PQ signature that achieves near-optimal signature generation efficiency with only a small, constant number of hash operations per signing. Its core innovation enables verifiers to obtain one-time hash-based public keys without interacting with signers or third parties through secure computation. We formally prove the security of LiteQS in the random oracle model and evaluate its performance on commodity hardware and a resource-constrained 8-bit AtMega128A1 microcontroller. Experimental results show that LiteQS outperforms NIST PQ standards with lower computational overhead, minimal memory usage, and compact signatures. On an 8-bit microcontroller, it achieves up to 1.5–24×higher energy efficiency and 1.7–22×shorter signatures than PQ counterparts, and 56–76×better energy efficiency than conventional standards–enabling longer device lifespans and scalable, quantum-resilient authentication. 

Federated learning (FL) is well-suited to 5G networks, where many mobile devices generate sensitive edge data. Secure aggregation protocols enhance privacy in FL by ensuring that individual user updates reveal no information about the underlying client data. However, the dynamic and large-scale nature of 5G-marked by high mobility and frequent dropouts-poses significant challenges to the effective adoption of these protocols. Existing protocols often require multi-round communication or rely on fixed infrastructure, limiting their practicality. We propose a lightweight, single-round secure aggregation protocol designed for 5G environments. By leveraging base stations for assisted computation and incorporating precomputation, key-homomorphic pseudorandom functions, and t-out-of-k secret sharing, our protocol ensures efficiency, robustness, and privacy. Experiments show strong security guarantees and significant gains in communication and computation efficiency, making the approach well-suited for real-world 5G FL deployments. 

In this paper, we outline a fast and lightweight network security fabric and identify the research gaps for developing such a fabric that respects the needs of trustworthy NextG SATIN for the post-quantum era. To achieve these objectives, we identify in which research directions more innovations are needed, namely algorithmic (NIST-PQC, distributed computing, time-disclosed cryptography), architectural (decentralized SATIN, distributed key management), and evaluation aspects. 

The rapid advancements in wireless technology have significantly increased the demand for communication resources, leading to the development of Spectrum Access Systems (SAS). However, network regulations require disclosing sensitive user information, such as location coordinates and transmission details, raising critical privacy concerns. Moreover, as a database-driven architecture reliant on user-provided data, SAS necessitates robust location verification to counter identity and location spoofing attacks and remains a primary target for denial-of-service (DoS) attacks. Addressing these security challenges while adhering to regulatory requirements is essential.In this paper, we propose SLAP, a novel framework that ensures location privacy and anonymity during spectrum queries, usage notifications, and location-proof acquisition. Our solution includes an adaptive dual-scenario location verification mechanism with architectural flexibility and a fallback option, along with a counter-DoS approach using time-lock puzzles. We prove the security of SLAP and demonstrate its advantages over existing solutions through comprehensive performance evaluations. 

Large-scale next-generation networked systems like smart grids and vehicular networks facilitate extensive automation and autonomy through real-time communication of sensitive messages. Digital signatures are vital for such applications since they offer scalable broadcast authentication with non-repudiation. Yet, even conventional secure signatures (e.g., ECDSA, RSA) introduce significant cryptographic delays that can disrupt the safety of such delay-aware systems. With the rise of quantum computers breaking conventional intractability problems, these traditional cryptosystems must be replaced with post-quantum (PQ) secure ones. However, PQ-secure signatures are significantly costlier than their conventional counterparts, vastly exacerbating delay hurdles for real-time applications. We propose a new signature called Time Valid Probabilistic Data Structure HORS (TVPD-HORS) that achieves significantly lower end-to-end delay with a tunable PQ-security for real-time applications. We harness special probabilistic data structures as an efficient one-way function at the heart of our novelty, thereby vastly fastening HORS as a primitive for NIST PQ cryptography standards. TVPD-HORS permits tunable and fast processing for varying input sizes via One-hash Bloom Filter, excelling in time-valid cases, wherein authentication with shorter security parameters is used for short-lived yet safety-critical messages. We show that TVPD-HORS verification is 2.7× and 5× faster than HORS in high-security and time-valid settings, respectively. TVPD-HORS key generation is also faster, with a similar signing speed to HORS. Moreover, TVPD-HORS can increase the speed of HORS variants over a magnitude of time. These features make TVPD-HORS an ideal primitive to raise high-speed time-valid versions of PQ-safe standards like XMSS and SPHINCS+, paving the way for real-time authentication of next-generation networks. 

As network services progress and mobile and IoT environments expand, numerous security concerns have surfaced for spectrum access systems (SASs). The omnipresent risk of Denial-of-Service (DoS) attacks and raising concerns about user privacy (e.g., location privacy, anonymity) are among such cyber threats. These security and privacy risks increase due to the threat of quantum computers that can compromise longterm security by circumventing conventional cryptosystems and increasing the cost of countermeasures. While some defense mechanisms exist against these threats in isolation, there is a significant gap in the state of the art on a holistic solution against DoS attacks with privacy and anonymity for spectrum management systems, especially when post-quantum (PQ) security is in mind. In this paper, we propose a new cybersecurity framework, PACDoSQ, which is the first to offer location privacy and anonymity for spectrum management with counter DoS and PQ security simultaneously. Our solution introduces the private spectrum bastion concept to exploit existing architectural features of SASs and then synergizes them with multi-server private information retrieval and PQ-secure Tor to guarantee a location-private and anonymous acquisition of spectrum information, together with hash-based client-server puzzles for counter DoS. We prove that PACDoSQ achieves its security objectives and show its feasibility via a comprehensive performance evaluation. 

Federated learning (FL) enables collaborative model training while preserving user data privacy by keeping data local. Despite these advantages, FL remains vulnerable to privacy attacks on user updates and model parameters during training and deployment. Secure aggregation protocols have been proposed to protect user updates by encrypting them, but these methods often incur high computational costs and are not resistant to quantum computers. Additionally, differential privacy (DP) has been used to mitigate privacy leakages, but existing methods focus on secure aggregation or DP, neglecting their potential synergies. To address these gaps, we introduce Beskar, a novel framework that provides post-quantum secure aggregation, optimizes computational overhead for FL settings, and defines a comprehensive threat model that accounts for a wide spectrum of adversaries. We also integrate DP into different stages of FL training to enhance privacy protection in diverse scenarios. Our framework provides a detailed analysis of the trade-offs between security, performance, and model accuracy, representing the first thorough examination of secure aggregation protocols combined with various DP approaches for post-quantum secure FL. Beskar aims to address the pressing privacy and security issues FL while ensuring quantum-safety and robust performance. 

Digital Twins (DT) virtually model cyber-physical objects via sensory inputs by simulating or monitoring their behavior. Therefore, DTs usually harbor vast quantities of Internet of Things (IoT) components (e.g., sensors) that gather, process, and offload sensitive information (e.g., healthcare) to the cloud. It is imperative to ensure the trustworthiness of such sensitive information with long-term and compromise-resilient security guarantees. Digital signatures provide scalable authentication and integrity with non-repudiation and are vital tools for DTs. Post-quantum cryptography (PQC) and forward-secure signatures are two fundamental tools to offer long-term security and breach resiliency. However, NIST-PQC signature standards are exorbitantly costly for embedded DT components and are infeasible when forward-security is also considered. Moreover, NIST-PQC signatures do not admit aggregation, which is a highly desirable feature to mitigate the heavy storage and transmission burden in DTs. Finally, NIST recommends hybrid PQ solutions to enable cryptographic agility and transitional security. Yet, there is a significant gap in the state of the art in the achievement of all these advanced features simultaneously. Therefore, there is a significant need for lightweight digital signatures that offer compromise resiliency and compactness while permitting transitional security into the PQ era for DTs. We create a series of highly lightweight digital signatures called Hardware-ASisted Efficient Signature (HASES) that meets the above requirements. The core ofHASES is a hardware-assisted cryptographic commitment construct oracle (CCO) that permits verifiers to obtain expensive commitments without signer interaction. We created threeHASES schemes:PQ-HASES is a forward-secure PQ signature,LA-HASES is an efficient aggregate Elliptic-Curve signature, andHY-HASES is a novel hybrid scheme that combinesPQ-HASES andLA-HASES with novel strong nesting and sequential aggregation.HASES does not require a secure-hardware on the signer. We prove thatHASES schemes are secure and implemented them on commodity hardware and and 8-bit AVR ATmega2560. Our experiments confirm thatPQ-HASES andLA-HASES are two magnitudes of times more signer efficient than their PQ and conventional-secure counterparts, respectively.HY-HASES outperforms NIST PQC and conventional signature combinations, offering a standard-compliant transitional solution for emerging DTs. We open-sourceHASES schemes for public-testing and adaptation. 

The Internet of Things (IoT) harbors a large number of resource-limited devices (e.g., sensors) that continuously generate and offload sensitive information (e.g., financial, health, personal). It is imperative the ensure the trustworthiness of this data with efficient cryptographic mechanisms. Digital signatures can offer scalable authentication with public verifiability and nonrepudiation. However, the state-of-the-art digital signatures do not offer the desired efficiency and are not scalable for the connected resource-limited IoT devices. This is without considering long term security features such as post-quantum security and forward security. In this paper, we summarize the main challenges to an energy-aware and efficient signature scheme. Then, we propose new scheme design improvements that uniquely embed different emerging technologies such as Mutli-Party Computation (MPC) and secure enclaves (e.g., Intel SGX) in order to secret-share confidential keys of low-end IoT devices across multiple cloud servers. We also envision building signature schemes with Fully Homomorphic Encryption (FHE) to enable verifiers to compute expensive commitments under encryption. We provide evaluation metrics that showcase the feasibility and efficiency of our designs for potential deployment on embedded devices in IoT. 

Digital signatures provide scalable authentication with non-repudiation and therefore are vital tools for the Internet of Things (IoT). IoT applications harbor vast quantities of low-end devices that are expected to operate for long periods with a risk of compromise. Hence, IoT needs post-quantum cryptography (PQC) that respects the resource limitations of low-end devices while offering compromise resiliency (e.g., forward security). However, as seen in NIST PQC efforts, quantum-safe signatures are extremely costly for low-end IoT. These costs become prohibitive when forward security is considered. We propose a highly lightweight post-quantum digital signature called HArdware-Supported Efficient Signature (HASES) that meets the stringent requirements of resource-limited signers (processor, memory, bandwidth) with forward security. HASES transforms a key-evolving one-time hash-based signature into a polynomial unbounded one by introducing a public key oracle via secure enclaves. The signer is non-interactive and only generates a few hashes per signature. Unlike existing hardware-supported alternatives, HASES does not require secure-hardware on the signer, which is infeasible for low-end IoT. HASES also does not assume non-colluding servers that permit scalable verification. We proved that HASES is secure and implemented it on the commodity hardware and the 8-bit AVR ATmega2560 microcontroller. Our experiments confirm that HASES is 271  and 34  faster than (forward-secure) XMSS and (plain) Dilithium. HASES is more than twice and magnitude more energy-efficient than (forward-secure) ANT and (plain) BLISS, respectively, on an 8-bit device. We open-source HASES for public testing and adaptation.