April 2012

Doc ID 022369 Rev 3

1/22

AN3992

Application note

Using an STM8L162M8 AES hardware accelerator with a CR95HF

to encrypt contactless tag data memory

Introduction

This application note describes STM8L162M8 demonstration firmware which reads and

writes encrypted data into an LRxk contactless tag. The MCU encrypts data using its

embedded AES hardware and sends it to a contactless tag through the CR95HF

transceiver.

The data stored into the contactless tag can be read by anyone but decrypted only by the

encryption or decryption key owner.

Figure 1.

Data encryption diagram

MS19972V1

ISO15693 RF

STM8L162M8

Plain data

Encrypted data

CR95HF

LRxk

contactless tag

ISO/IEC 15693 RF

transaction

SPI or UART bus

AES hardware

RF communication

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