Exam CAS-004 topic 1 question 250 discussion

For safety-critical systems, CAN is the most widely used communication protocol and does not have a built-in encryption mechanism. This prioritizes low latency and deterministic response times over encryption. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7219335/

In real-time, safety-critical systems, the primary concern is ensuring that the system behaves in a predictable and reliable manner to meet safety requirements. Given this focus, the correct choice from the options provided is D. Have deterministic behavior and are not deployed with encryption. Here’s why: Deterministic Behavior: Real-time systems require deterministic behavior to ensure that data is transmitted and processed within strict time constraints. This predictability is crucial for maintaining the safety and reliability of the system. Encryption: While encryption is important for security and protecting data from unauthorized access, it is not typically the primary concern for real-time, safety-critical systems when compared to the need for deterministic behavior. These systems often focus on the reliability and timing of data transfer rather than encryption. Therefore, for real-time, safety-critical systems, deterministic behavior is paramount, and encryption is not always a requirement or priority in these contexts.

Deterministic Behavior: Safety-critical systems require predictable and reliable communication to ensure that tasks are executed within strict time constraints. Deterministic behavior in serial busses ensures that data transmission occurs in a predictable manner, which is essential for the correct functioning of real-time systems. Encryption: While encryption is crucial for securing data, it can introduce latency and overhead that might be unacceptable in real-time, safety-critical environments. In these contexts, the focus is often on ensuring that data is transmitted accurately and timely rather than encrypted, to maintain the system's performance and reliability.

It's a serial bus, not a networked server. How much encryption is going on in the serial bus of the computer you're on right now? How much encryption happens between any two hardlinked components or machines? I'm not even sure modern laptops have any serial I/Os in them, but the point is that you don't need to encrypt non-networked pieces of your infrastructure. encryption would be overkill and generally counterproductive in a single-bit-at-a-time hardlined proprietary-safety-message-sendy-machine.

safety critical systems without encryption is insane. You would consider a different system and topology for a SAFETY CRITICAL system than using a CAN.

Deterministic means it contains a field that has info regarding message priority. Can bus is one such serial bus, and by default does not have encryption, although it can have.

Option D. Deploying encryption on serial busses may introduce additional processing overhead and introduce delays, which can adversely affect the timing and predictability of the critical systems. Therefore, safety-critical systems that use serial busses typically do not use encryption, as the need for predictable, deterministic behavior takes priority over data confidentiality.

Deterministic behavior is critical for these systems, as it ensures that tasks are executed in a predictable and reliable manner

from what I read online, the CAN bus is a broadcast network and isn't designed with encryption in mind. I was trying to tie CAN busses to safety critical systems and found 1 or 2 articles mentioning it. I was originally thinking C because encryption seems like a no brainer for mission critical applications or use cases, but apparently, no encryption (yet) on CAN busses

c. i apologize. The answer is C

eal-time safety-critical systems require deterministic behavior to ensure that specific tasks are carried out within a defined timeframe. Serial busses that have deterministic behavior can guarantee that messages are sent and received at a predictable rate, which is essential for these systems to operate as intended. Additionally, security is also critical for safety-critical systems, and deploying serial busses with encryption provides an added layer of protection against unauthorized access, tampering, or data breaches.