Verfahren und Vorrichtung zum Schutz von durch einen Eingebetteten Mikroprozessor Verarbeiteten Code vor Veränderung

Details

Veröffentlichungs-Nr.

EP3509003

Aktenzeichen

EP18150269

Anmeldetag

4. Januar 2018

Veröffentlichung

21. April 2021

Erteilung

21. April 2021

Rechtsraum

EP

IPC

G06F21/57

Abstract

The invention discloses a method to protect code processed by an embedded micro-processor against altering and an apparatus using the inventive method. The object of the invention to provide a solution for security problems caused by cache usage on platforms with embedded processors and external memory will be solved by a method comprising the following steps: reading immutable boot code from a ROM; loading a code image from an external memory and calculating a hash by a core unit; initially authenticating the hash using the boot code for decrypting the hash of the external memory; whereas concurrently calculating a salted hash for each equivalent of a cache line of the code image by a cache protection block; storing the salted hash for each cache line in an internal hash table; whereas if the authentication succeeds, a part of the code image is loaded into a secure cache of the embedded micro-processor; otherwise if a secure cache miss occurs, the code image is reloaded from the external memory and the salted hash for the missed cache line is re-calculated by the cache protecting block and is checked against the stored salted hash in the internal hash table.

Anmelder

Firmen

Shenzhen Goodix Technology Co., Ltd.
Commsolid GmbH

Land

🇨🇳 China

Fachgebiete