Trustworthiness for embedded nodes is a critical point when involved devices are resources-constrained and remotely installed. In particular, the software execution environment is jeopardized by physical attacks aimed to extract secrets:
Physically Unclonable Functions are physical entities that maps a set of challenges to a set of response forming a set of challenge-response pairs (CPRs). A PUF exploits random imperfections introduced indirectly into the device during its manufacturing process. Its feature can be exploited to generate response that are:
- Unique for each device where the PUF is implemented,
- Unclonable,
- Unpredictable,
- Tamper-evident.
For this reasons, PUFs represent a breakthrough for silicon devices as they can be exploited as secure primitive. Silicon PUF term indicates PUF characterized by a behavior physically imprinted into integrated circuits (ICs) in which PUFs are embedded.
In this work, using a specific Silicon PUF available into most
In this paper we illustrate a
pragmatic key extraction and management methodology using a specific Silicon PUF available on modern microcontroller architectures, with a real application on the STM32F7 microcontroller family, in which extracted keys are involved for remote update of ciphered software images.