4 ms·

Data diodes exist and have been used in high security or other risky cases when one circuit or bus absolutely has to be isolated except for one way communicatio

Data diodes exist and have been used in high security or other risky cases when one circuit or bus absolutely has to be isolated except for one way communication. In practice it's not typically necessary to go quite that far if a trusted communication processor is able to pass messages or set registers but only ever takes logic control flow input from the "safe" side. Plenty of equipment that wants to broadcast state over radio but never accepts any sort of input back beyond acks or whatever has done this for a long time.

TeMPOraL 6y ago
I was talking about two-way communications. Maybe you can securely isolate a bus that has the insecure->secure side reduced to super trivial communication. But I won't trust anything that runs multi-layer software stack and a complex communications protocol; from what I've learned about software security, there's always a bug or a backdoor that can be exploited to elevate access or just break the secure-side components. (This is, of course, entirely my opinion. I haven't seen the code of these systems, but looking from the outside, nothing I've learned makes me feel like I can trust their security.)
- EvanAnderson 6y ago
  When I saw arbitrary code execution on the NES in Super Mario 3 done with only controller inputs I decided any notion of software security in a system more complex than, say, a microwave oven, wasn't achievable. I recently heard an "On Star" ad that proclaimed that they can "slow down stolen cars". Consumers are wowed by features that, by definition, are enabled by unwise security decisions. Manufacturers will cash in. IT security in cars will get worse.
Silhouette 6y ago
Data diodes exist and have been used in high security or other risky cases when one circuit or bus absolutely has to be isolated except for one way communication. But how can you include adequate firewalls in a car that, for example, receives OTA updates for autonomous driving software? It is inherent in any such system that incoming signals are received and that the software that may be affected by those signals has access to pretty much everything.

TeMPOraL 6y ago

I was talking about two-way communications. Maybe you can securely isolate a bus that has the insecure->secure side reduced to super trivial communication. But I won't trust anything that runs multi-layer software stack and a complex communications protocol; from what I've learned about software security, there's always a bug or a backdoor that can be exploited to elevate access or just break the secure-side components. (This is, of course, entirely my opinion. I haven't seen the code of these systems, but looking from the outside, nothing I've learned makes me feel like I can trust their security.)

EvanAnderson 6y ago
When I saw arbitrary code execution on the NES in Super Mario 3 done with only controller inputs I decided any notion of software security in a system more complex than, say, a microwave oven, wasn't achievable. I recently heard an "On Star" ad that proclaimed that they can "slow down stolen cars". Consumers are wowed by features that, by definition, are enabled by unwise security decisions. Manufacturers will cash in. IT security in cars will get worse.

Silhouette 6y ago

Data diodes exist and have been used in high security or other risky cases when one circuit or bus absolutely has to be isolated except for one way communication. But how can you include adequate firewalls in a car that, for example, receives OTA updates for autonomous driving software? It is inherent in any such system that incoming signals are received and that the software that may be affected by those signals has access to pretty much everything.