Juan Villacis’s research while affiliated with University of Bern and other places

In protocols with asymmetric trust, each participant is free to make its own individual trust assumptions about others, captured by an asymmetric quorum system. This contrasts with ordinary, symmetric quorum systems and with threshold models, where all participants share the same trust assumption. It is already known how to realize reliable broadcasts, shared-memory emulations, and binary consensus with asymmetric quorums. In this work, we introduce Directed Acyclic Graph (DAG)-based consensus protocols with asymmetric trust. To achieve this, we extend the key building-blocks of the well-known DAG-Rider protocol to the asymmetric model. Counter to expectation, we find that replacing threshold quorums with their asymmetric counterparts in the existing constant-round gather protocol does not result in a sound asymmetric gather primitive. This implies that asymmetric DAG-based consensus protocols, specifically those based on the existence of common-core primitives, need new ideas in an asymmetric-trust model. Consequently, we introduce the first asymmetric protocol for computing a common core, equivalent to that in the threshold model. This leads to the first randomized asynchronous DAG-based consensus protocol with asymmetric quorums. It decides within an expected constant number of rounds after an input has been submitted, where the constant depends on the quorum system.

En países en desarrollo como Ecuador, es crucial incrementar la capacidad energética para respaldar la industrialización y fomentar un crecimiento económico sostenible. Una planificación estratégica eficiente en el sector energético resulta esencial para minimizar los costos vinculados a la generación y el transporte de energía eléctrica, y para asegurar un suministro confiable y eficiente. Este estudio introduce un modelo de programación lineal entera mixta (MILP) para una planificación multietapa de la expansión integrada de generación y transmisión de energía. El modelo se aplica al sistema eléctrico ecuatoriano, específicamente a un caso de prueba propuesto de 56 nodos (56-Bus SNI Ecuador System), se evalúa el período de 2018 a 2031. Este modelo demuestra que las actuales iniciativas del Plan Maestro de Electricidad son suficientes para cubrir la futura demanda proyectada. La generación hidroeléctrica se mantendría predominante con el 76.60 % de participación en 2031. Paralelamente, la generación térmica, pese a representar solo el 22.51 % de la producción futura, incurre en el 81.90 % de los costos operativos, lo que plantea significativos desafíos de eficiencia económica y sostenibilidad ambiental. De ahí que, es fundamental diversificar la matriz energética y optimizar la planificación para una transición energética sostenible en el contexto de escasez de recurso hídrico cada vez más recurrente en Ecuador.

Introduction Chagas disease is a neglected tropical disease caused by the parasite Trypanosoma cruzi that is transmitted mainly by the feces of infected Triatomines. In Ecuador the main vector is Rhodnius ecuadoriensis which is distributed in several provinces of the country. More than 40% of these insects in the wild have T. cruzi as part of their intestinal microbiota. For this reason, the objective of this research was to characterize the intestinal bacterial microbiota of R. ecuadoriensis. Methods The methodology used was based on the DNA extraction of the intestinal contents from the wild collected insects (adults and nymphs V), as well as the insects maintained at the insectary of the CISeAL. Finally, the samples were analyzed by metagenomics extensions based on the different selected criteria. Results The intestinal microbiota of R. ecuadoriensis presented a marked divergence between laboratory-raised and wild collected insects. This difference was observed in all stages and was similar between insects from Loja and Manabí. A large loss of microbial symbionts was observed in laboratory-raised insects. Discussion This study is a crucial first step in investigating microbiota interactions and advancing new methodologies.

Many blockchain networks aim to preserve the anonymity of validators in the peer-to-peer (P2P) network, ensuring that no adversary can link a validator's identifier to the IP address of a peer due to associated privacy and security concerns. This work demonstrates that the Ethereum P2P network does not offer this anonymity. We present a methodology that enables any node in the network to identify validators hosted on connected peers and empirically verify the feasibility of our proposed method. Using data collected from four nodes over three days, we locate more than 15% of Ethereum validators in the P2P network. The insights gained from our deanonymization technique provide valuable information on the distribution of validators across peers, their geographic locations, and hosting organizations. We further discuss the implications and risks associated with the lack of anonymity in the P2P network and propose methods to help validators protect their privacy. The Ethereum Foundation has awarded us a bug bounty, acknowledging the impact of our results.