Engineering memory-efficient bootloaders capable of verifying large post-quantum digital signatures within severe micro-RAM constraints.
Many industrial sensor microcontrollers feature only 32 KB to 64 KB of total RAM. Loading an entire ML-DSA-65 signature (3,293 bytes), public key (1,952 bytes), and firmware hash into memory simultaneously leaves virtually no memory for the operating system or application runtime.
We explain how to stream firmware binaries through hardware Keccak hash engines in 512-byte chunks, computing the final digest without buffering the complete image. We analyze lightweight hash-based signatures (LMS/XMSS) that verify in less than 2 KB of working SRAM.
Designing hardware-enforced monotonic counter registers and fallback recovery partitions that protect resource-constrained field devices from malicious firmware downgrades.