KeyM

KeyM stands for Key Manager, a module of the AUTOSAR Classic Platform Crypto Stack defined in the AUTOSAR Specification of Key Manager. It gives applications and other basic-software modules one interface for installing and updating keys and for working with certificates, so key-handling logic is not scattered across SecOC, diagnostics, secure boot and OTA code.

CSM (Crypto Service Manager) performs cryptographic operations — encryption, MAC generation, signature verification, hashing — while KeyM manages the keys and certificates those operations depend on. KeyM decides which key material and certificate chains are installed and valid, and it uses CSM jobs for the underlying cryptography, which CryIf then routes to a hardware or software crypto driver.

KeyM is used in ECUs that must install, rotate or verify keys and certificates in the field. Typical uses are provisioning SecOC keys at end-of-line or in the workshop, validating the certificate chain of a signed software update before flashing, and checking certificates presented during UDS authentication (service 0x29) or secure vehicle-to-backend connections.