  The Internet of Things (IoT) represents a significant advancement in digital
technology, with its rapidly growing network of interconnected devices. This
expansion, however, brings forth critical challenges in data security and
reliability, especially under the threat of increasing cyber vulnerabilities.
Addressing the security concerns, the Advanced Encryption Standard (AES) is
commonly employed for secure encryption in IoT systems. Our study explores an
innovative use of AES, by repurposing AES padding bits for error correction and
thus introducing a dual-functional method that seamlessly integrates
error-correcting capabilities into the standard encryption process. The
integration of the state-of-the-art Guessing Random Additive Noise Decoder
(GRAND) in the receiver's architecture facilitates the joint decoding and
decryption process. This strategic approach not only preserves the existing
structure of the transmitter but also significantly enhances communication
reliability in noisy environments, achieving a notable over 3 dB gain in Block
Error Rate (BLER). Remarkably, this enhanced performance comes with a minimal
power overhead at the receiver - less than 15% compared to the traditional
decryption-only process, underscoring the efficiency of our hardware design for
IoT applications. This paper discusses a comprehensive analysis of our
approach, particularly in energy efficiency and system performance, presenting
a novel and practical solution for reliable IoT communications.
