Deliverables
There are different ways to make sensors trustworthy. One can make use of trusted hardware such as Trusted Platform Module (TPM), or avail trusted distributed neighbors and ambient information that cannot be challenged.
Deliverables:
• Thoroughly research the field of trusted sensing
• Case studies for two sensors on how they can be attacked and ways to secure them
• Come up with a good abstraction for trusted sensor and implement on an embedded or smartphone platform for one use case
Our goal is to ensure security of two sensors: audio and video both of which can be used to confirm the authenticity of a video footage or audio recording.
The idea is to simply associate a digital signature to provide both authenticity and integrity for the sensor reading. To offer these two properties, the sensor reading is signed. The key used for signing is a Trusted Platform Module (TPM)’s Attestation Identity Key (AIK). The sensor attestation must also incorporate a notion of the sensor’s state to ensure that software can correctly interpret how the reading was produced.
Reliability and Security:
We can attest the sensor readings integrity by adding a verifier that can check the signature associated with the public part of the key. We can design an API in such a way that whenever an application calls a function that returns sensor data, it also provides an additional parameter for the signature, and this signature should cover all of the output data.
The API is designed by drafting all possible readings the sensor can produce, for example. The Camera sensor will have corresponding settings such as the exposure and ISO which needs to be represented in the API. This allows the user to recognize the state of the camera. The signature for a sensor reading then encompasses the sensor’s data as well as the configuration state. Ideally the trusted sensor API should read from the specified sensor hardware, sign the readings with a private signing key. For the project we aim to sign a SHA-1/SHA-256 hash of the data using the private RSA key. The private signing key can be kept confidential and the public key ( which could be TPM’s AIK cer-tificate) and the TPM’s version of the public key are all stored to be used for future usage.