Articles publicats (Matemàtica)
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- ItemOpen AccessBio-Integrated Hybrid TESLA: A Fully Symmetric Lightweight Authentication Protocol(IEEE, 2024) Eledlebi, Khouloud; Alzubaidi, Ahmed Adel; Damiani, Ernesto; Puthal, Deepak; Mateu Meseguer, Víctor; Zemerly, Mohammed Jamal; Al-Hammadi, Yousof; Yeun, Chan YeobThe rapid integration of the IoT devices into everyday decision-making processes underscores the need for continuous user authentication and data integrity checking during network communication, all while minimizing energy consumption to extend device lifespan. This article introduces the bio-integrated hybrid timed-efficient stream loss-tolerant authentication (TESLA) protocol, which is a fully symmetric and energy-efficient authentication protocol designed for the resource-constrained IoT devices. Based on the hybrid TLI- μ TESLA protocol, this innovative solution prioritizes high cybersecurity levels and minimal computational requirements for continuous authentication. An innovative advancement involves eliminating the public cryptography process during the synchronization stage of the TESLA protocols. Instead, biometric authentication through the distorted fingerprint and electroencephalogram templates is employed, to establish a nonshared symmetric session key, utilized only once. Furthermore, neither the key nor the original biometric templates are transmitted over the network, ensuring user identity preservation and effectively resolving the key distribution challenge inherent in symmetric cryptography. By offloading intensive tasks to the servers and avoiding the storage or transmission of biometric data, the proposed approach conserves the IoT device energy and enhances cybersecurity. Simulation analyses and cybersecurity assessments demonstrate successful synchronization, privacy preservation, and low computational demands compared to the existing protocols, making the bio-integrated hybrid TESLA protocol a significant advancement in IoT authentication.
- ItemOpen AccessComparative study of novel packet loss analysis and recovery capability between hybrid TLI-µTESLA and other variant TESLA protocols(Elsevier, 2024) Eledlebi, Khouloud; Alzubaidi, Ahmed Adel; Damiani, Ernesto; Mateu Meseguer, Víctor; Al-Hammadi, Yousof; Puthal, Deepak; Yeun, Chan YeobAnalyzing packet loss, whether resulting from communication challenges or malicious attacks, is vital for broadcast authentication protocols. It ensures legitimate and continuous authentication across networks. While previous studies have mainly focused on countering Denial of Service (DoS) attacks' impact on packet loss, our research introduces an innovative investigation into packet loss and develops data recovery within variant TESLA protocols. We highlight the efficacy of our proposed hybrid TLI-µTESLA protocol in maintaining continuous and robust connections among network members, while maximizing data recovery in adverse communication conditions. The study examines the unique packet structures associated with each TESLA protocol variant, emphasizing the implications of losing each type on the network performance. We also introduce modifications to variant TESLA protocols to improve data recovery and alleviate the effects of packet loss. Using Java programming language, we conducted simulation analyses that illustrate the adaptability of variant TESLA protocols in recovering lost packet keys and authenticating previously buffered packets, all while maintaining continuous and robust authentication between network members. Our findings also underscore the superiority of the hybrid TLI-µTESLA protocol in terms of packet loss performance and data recovery, alongside its robust cybersecurity features, including confidentiality, integrity, availability, and accessibility. Additionally, we demonstrated the efficiency of our proposed protocol in terms of low computational and communication requirements compared to earlier TESLA protocol variants, as outlined in previous publications.
- ItemOpen AccessSome inner metric parameters of a digraph: iterated line digraphs and integer sequences(Sociedad Matemática Mexicana, 2024-10) Bong, N.H.; Dalfó, Cristina; Fiol Mora, Miguel Ángel; Závacká, DominikaIn this paper, we first give a new result characterizing the strongly connected digraphs with a diameter equal to that of their line digraphs. Then we introduce the concepts of the inner diameter and inner radius of a digraph and study their behaviors in its iterated line digraphs. Furthermore, we provide a method to characterize sequences of integers (corresponding to the inner diameter or the number of vertices of a digraph and its iterated line digraphs) that satisfy some conditions. Among other examples, we apply the method to the cyclic Kautz digraphs, square-free digraphs, and the subdigraphs of De Bruijn digraphs. Finally, we present some tables with new sequences that do not belong to The On-Line Encyclopedia of Integer Sequences.
- ItemOpen AccessHeterospecific visual cues and trophic facilitation processes used by a solitary bone-eating vulture(John Wiley and Sons Inc., 2024) Oliva-Vidal, Pilar; Villalba Mata, Daniel; Colomer, M. Àngels (Maria Àngels); Margalida, AntoniWhile the influence of public information sharing on foraging strategies is of growing interest, empirical studies exploring intraguild social information use and facilitation roles between individuals with different trophic specializations remain scarce. Heterospecific facilitation should be more common in specialist foragers, for example, the bearded vulture Gypaetus barbatus, a solitary bone-eating scavenger. We monitored 133 carcasses of different types/sizes in open and shrubland landscapes in the Spanish Pyrenees to explore bearded vulture foraging in relation to social information transfer and adaptive trophic behavior. We hypothesized that they might (1) feed on carcasses after initial heterospecific exploitation; (2) use heterospecifics to locate and/or exploit carcasses; and (3) prefer old carcasses over fresh ones. We recorded bearded vultures scavenging at 44 carcasses; 95.5% had been previously exploited by heterospecifics (93.2% by griffon vultures Gyps fulvus and 2.3% by golden eagles Aquila chrysaetos) while only two small-sized carcasses were scavenged without previous heterospecific exploitation. Bearded vultures were not observed scavenging at carcasses used only by mammals. Both griffon and bearded vultures took longer to find carcasses in shrublands than in open landscapes. However, bearded vulture arrival times between landscapes after carcass discovery by griffon vultures were similar. Bearded vultures were more likely to discover a carcass the greater the number of griffon vultures exploiting it. Only 10.4% bearded vulture scavenging events occurred after the third week following heterospecific exploitation, suggesting that recently opened carcasses were preferred. Clearly, heterospecifics play an essential role in bearded vultures foraging success, and griffon vultures are fundamental facilitators for specialist foragers, both in providing visual cues to food location and in opening up carcasses to enable access to food.
- ItemOpen AccessGrupo de Estadística Espacio-Temporal(Sociedad de Estadística e Investigación Operativa, 2023) Comas Rodríguez, CarlesLa estadística espacio-temporal engloba todas las herramientas matemáticas para el análisis, modelización y simulación de datos estadísticos que ocurren en un contexto espacial o espacio-temporal. Los tópicos de interés abarcan el análisis estadístico de patrones puntuales espaciales, datos geoestadísticos y datos espaciales en retícula, incluyendo para todos ellos sus extensiones al dominio espacio-temporal.