Resource-constrained Internet of Things (IoT) devices motivate the investigation into cryptographic designs with measurable implementation costs. This work presents CHIMA (Cryptography cHaotic lIghtweight systeM and Authentication), an experimental system combining a key generator based on chaotic states, a Feistel cipher using the AES substitution box and a keyed bit permutation, and a Lesamnta-LW-based ciphertext check. Logistic, H’enon, and Lorenz systems are examined for key generation, and cipher variants with 64-bit and 128-bit blocks are evaluated. The study reports functional tests, avalanche measurements, NIST statistical tests, and implementation measurements on Arm Cortex-M0+, Cortex-M33, and Cortex-M7 microcontrollers. Controlled WiFi/MQTT and LoRa experiments assess communication interoperability. The results show that the chaotic key generator achieved high entropy and passed all NIST statistical tests, indicating its suitability for generating pseudorandom sequences. Based on the combined encryption and decryption times, CHIMA-64 requires 57.95–64.16% less time than PRESENT, while CHIMA-128 requires 23.60–59.36% less time than AES-128 and 13.32–47, as well as 10% less time than CLEFIA across the three platforms.

Although Brazil is in the last mile of achieving universal electricity access, the Amazon region represents the country’s most critical electrification frontier, where remote energy expansion has largely failed to integrate clean alternatives. This study presents the design and techno-economic assessment of a hybrid off-grid microgrid tailored for the Amazon, incorporating a multi-source architecture that combines micro-hydro (MH), wind power (WT), solar photovoltaics (PV), diesel generation (DG), and battery energy storage systems (BESS). Three locations in Amazonas, Roraima, and Tocantins were evaluated under three scenarios: a hybrid system with DG, a fully renewable system without DG, and a green scenario that accounts for demand-side flexibility and selected technical and economic conditions. Optimization was performed using the HOMER tool for a typical isolated community. The hybrid configuration achieved a DG generation share of 0.7 (RSS, DG–WT–PV–MH–BESS), 0.9% (Jalapão, DG–WT–PV–MH–BESS), and 6.8% (Labrea, DG–PV–BESS). The fully renewable scenario resulted in Levelized Cost of Energy (COE) values ranging from 0.146 USD/kWh (RSS) to 0.388 USD/kWh (Lábrea), while the green scenario yielded COEs between 0.089 USD/kWh (RSS) and 0.190 USD/kWh (Lábrea). This study reveals the role of MH in reducing storage requirements, installed capacity, and system cost. The results are promising for presenting a competitive cost of energy.