Is Rust suitable to implement communication and encryption protocols as well as intrusion detection systems in resource-constraint environments like sensor nodes in WSNs?
Which limitations are there compared to C/C++? Also with regard to the limitations of the manufacturer APIs and existing operating systems and whatsoever.
I'm currently learning Rust and will afterwards dive into embedded Rust. If Rust isn't yet suitable for my intended application, will it be suitable in the foreseeable future?
Sure!
You can check out more at Embedded devices, but summarized it's very, very good for embedded development - as a technology. It has better memory safety than the C-family, it's optimized for fast compilation in the current paradigm and it seems to be doing okay with concurrency (okay-er than Embedded C). It also seems to be fairly well-balanced with newer microprocessors, which knowing the hoops some producers are jumping through recently to push out their products on the market - will definitely help you if you run into particularly janky components (which in my experience of budget electronics, you will encounter a lot with clone producers) Besides, you can integrate it with an already existing C codebase so you can add your new code to a priory existing example of an application which does what you want your Rust application to do, then reverse-engineer it. This will be a great help for you if you're starting out now.
Somewhat paradoxically, I would also strongly advise you to wait if you want to start your career in this direction. Rust is absolutely not mature enough for complex projects on an industrial scale. On one hand most producers of chips don't care much for it - so for the moment it's a one-way relationship with small producers. On the other hand, some of my contacts have had some strange bugs while wrapping up and starting testing their prototypes including, but not limited to, unexplained behaviors and even stack overflows due to not-so-great libraries being worked on at an accelerated rate and not being cleaned all the time.