EVITA Medium/Full HSM Integration: Isolated Cryptographic Cores and Secure Keystores

The EVITA (E-safety Vehicle Intrusion Protected Applications) specification defines three tiers of on-chip security: EVITA Small (sensors/actuators), EVITA Medium (chassis/powertrain ECUs), and EVITA Full (central gateways and telematics).

An EVITA Full Hardware Security Module (HSM) contains its own dedicated processing core (e.g., ARM Cortex-M0+ or proprietary RISC), isolated RAM, true random number generator (TRNG), and cryptographic hardware accelerators (AES, SHA-256/384, ECC). The host application CPU cannot access the HSM's internal memory; communication occurs exclusively via secure mailbox registers, guaranteeing that root keys remain inaccessible even in the event of an arbitrary code execution exploit on the main operating system.