SDAA472 August   2026 MSPM33C321A

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Key Concepts
  5. 2Customer Secure Code Overview
    1. 2.1 Boot and Startup Sequence
    2. 2.2 CSC Flow
    3. 2.3 FLASH Memory Map
    4. 2.4 Bank Swap
    5. 2.5 CSC Feature
      1. 2.5.1 Asymmetric Verification
        1. 2.5.1.1 SHA-256
        2. 2.5.1.2 ECDSA
        3. 2.5.1.3 MLDSA
      2. 2.5.2 Keystore
    6. 2.6 Protection on CSC
      1. 2.6.1 Write Erase Protection
      2. 2.6.2 FLASH Hide Protection
      3. 2.6.3 Data Integrity Verification
      4. 2.6.4 Secure & Privilege Protection
    7. 2.7 CSC Performance
  6. 3Evaluate CSC-based Secure Boot
    1. 3.1 Environment Setup
    2. 3.2 Program CSC
      1. 3.2.1 General
      2. 3.2.2 Step 1 - Building
      3. 3.2.3 Step 2 - Programming
    3. 3.3 Program Application
      1. 3.3.1 General
      2. 3.3.2 Step 1 - Application Image Generation – Image 1 (version 1.0.0, Located at Bank 0 – 0x10000)
      3. 3.3.3 Step 2 - Application Image Generation – Image 2 (version 2.0.0, Located at 0x20000)
      4. 3.3.4 Step 3 - Programming
    4. 3.4 Running the CSC Application
  7. 4Q&A
    1. 4.1 How to Modify the Application Image Version
      1. 4.1.1 Application Image
    2. 4.2 How to Modify the Application Image Address
      1. 4.2.1 Application Image
      2. 4.2.2 Application Image Sign Command
      3. 4.2.3 CSC Example Code
    3. 4.3 How to Modify the Slot Size
      1. 4.3.1 Application Image
      2. 4.3.2 CSC Example Code
    4. 4.4 How to Modify the Application Image Size
      1. 4.4.1 Application Image
      2. 4.4.2 Modification on Slot Size
    5. 4.5 Doing More Customization on Application Image or CSC
  8. 5References
  9. 6Revision History

2.5.1.2 ECDSA

Elliptic curve digital signature algorithm (ECDSA) is a cryptographic algorithm used for digital signatures, based on elliptic curve mathematics. ECDSA offers high security with much shorter key lengths compared to traditional algorithms like RSA, making this algorithm efficient and designed for resource-constrained environments.

ECDSA is one supported authentication method for MCUboot. ECDSA is an asymmetric algorithm, meaning there is a separate public and private key. The public key is stored in the device flash, and the developer maintains the private key. CSC does not provide secure private key management.

ECDSA uses the hash of the image and the public key to verify a digital signature (r, s), checking the authenticity of the data. Compared to symmetric cryptographic options, this option does not present a key vulnerability on the device.

Note: To keep the boot flow for final deployment, keep the private key secure and managed so that the key is not easily accessible to sign images. Keeping the key on a local share drive is not a secure location! TI does not currently provide secure private key management.