September 2013

Doc ID024189 Rev 2

1/30

AN4240

Application note

Introduction to the Cryptographic Service Engine (CSE) module for

SPC56ECxx and SPC564Bxx devices

Introduction

This application note provides an easy introduction to the usage of the CSE module inside the

SPC56ECxx and SPC564Bxx family of devices.

The CSE module implements the security functions described in the Secure Hardware Extension (SHE)

functional specification version 1.1.

Three examples show main the features of the cryptographic service engine and in the same time the

differences between the Electronic Code Book (ECB), and the Cipher Block Chaining (CBC) mode of the

Advanced Encryption Standard (AES) algorithm, defined by SHE specification.

In particular, first example shows how to load cryptographic keys into secure flash in order to permit the

usage of the cryptographic module. Second application code shows that if a data or an image has a low

variance, the CBC cipher mode provides a best performance in terms of message encryption in

comparison with the ECB cipher mode. Last example code shows how to release a Secure Boot in order

to prevent application code from being altered by an unauthorized party cipher.

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