Performance of CRYSTALS-Kyber on Raspberry Pi 5 under Embedded-System Constraints: A Comparison with RSA and EC-KEM

The emergence of quantum computers presents a significant risk to public key cryptography algorithms, including RSA and elliptic curve cryptography (ECC). CRYSTALS-Kyber, also called Kyber, was standardized by NIST as the Module-Lattice-based-Key Encapsulation Mechanism (ML-KEM, FIPS 203) to address quantum threats. However, its performance on modern embedded ARM platforms remains uncharacterized. The aim of this study is to benchmark the Kyber family, including Kyber-512, Kyber-768, and Kyber-1024, on the Raspberry Pi 5, which is selected to represent embedded-system constraints. In addition, RSA and EC-KEM were chosen as baseline comparisons. Execution time, memory consumption (RSS), and key/ciphertext sizes were measured over 1,000 iterations using custom Python scripts (liboqs 0.14.0 and the Python cryptography library) on 64-bit Ubuntu Linux under controlled parallel execution. The results show that Kyber achieves sub-millisecond execution times (0.05-0.21 ms) for key generation, encapsulation, and decapsulation with low variability (SD < 0.02 ms). Nevertheless, RSA-2048 requires 250-264 ms per operation, while EC-KEM ranges from 0.29 ms for X25519 to 3.04 ms for secp521r1. Memory consumption is comparable across all algorithms (24-25 MB RSS). Kyber’s larger keys and ciphertexts (800-1568 bytes vs. 32-294 bytes for RSA/EC-KEM) present a latency-bandwidth trade-off for embedded deployments. Therefore, Kyber is computationally viable for latency-sensitive operations on modern ARM embedded systems. The evaluation focuses on discrete cryptographic operations, protocol-level integration and energy measurements are deferred to future work.