9 Security Module

The security module protects the operation of the device and intellectual property from unauthorized access, use and modification. The following security features are available on the dsPIC33AK512MPS512 family of devices:

  • Secure Boot
  • Secure Debug
  • Immutable Root of Trust (IRT)
  • Code Protect
  • ICSP Program/Erase Disable (Entire Flash OTP by ICSP Write Inhibit)
  • Firmware IP Protection
  • Flash Write Protection
  • Cryptographic Accelerator

The security features can be characterized into four categories:

Device Locking prevents unauthorized external access via debugger or programmer ICSP interfaces (local attacks). Device locking features include code protect, entire Flash OTP by ICSP write inhibit and secure debug.

The Immutable Root of Trust (IRT) partition protects IRT firmware and data for implementation of secure boot, secure debug, device attestation and other security functions.

Eight Configurable Protection Regions provide flexible user program Flash access control. The protection regions include: IRT partition, immutable device firmware (OTP), firmware IP protection (execute-only memory), Flash write-protection and code Flash partitioning.

Flash Access Control is provided for the executive, user OTP and user configuration Flash spaces.

The Cryptographic Accelerator features the following crypto functions:
  • True Random Number Generator (TRNG) - with NIST 800-90B compliant entropy source and health tests
  • AES
    • NIST compliant “Advanced Encryption Standard” (AES), FIPS 197
    • Encryption and Decryption with:
      • Non-chaining: ECB, CTR
      • Chaining: CBC, CFB, OFB
      • Cyphertext stealing: CBC-CS
      • Authentication and confidentiality: CCM, GCM
      • Confidentiality on storage: XTS/XTS-CS
        • Authentication with CMAC (OMAC1) mode
        • Supports 128-, 192- or 256-bits cipher key size
        • Optional: Masking based countermeasure to improve resistance against SPA and DPA attacks
  • Hash
    • FIPS 180-3 compliant HASH functions
    • SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512
    • FIPS-198-1 compliant HMAC support for all hash algorithms
  • Asymmetric Crypto Accelerator
    • RSA, DSA, DH, ECDH, ECDSA, EdDSA, J-PAKE and SRP
    • RSA, DSA and DH algorithms support up to 4096-bit key sizes
    • Standard ECC curves include: P256, P384, P521, P191, Curve25519 and Ed25519
    • Other ECC curves like Brainpool, Koblitz, Montgomery and Edwards curves supported via custom parameters
    • Rabin-Miller Primality tests
    • J-PAKE and SRP based secure password-authentication protocols
    • Optional: Randomization-based countermeasures