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Comment by Gibbon1 | Hacker News Reader

Not sure if types will force the compiler to do things like constant time comparisons and overwrite sensitive information as it goes out of scope.

I think Java, C#, and C/C++ the compiler will decide that code to clear memory just before it goes out of scope has no side effects and optimize that code away.

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You can definitely rig up the erasure to happen in a destructor (C++) or Drop implementation (Rust). Convincing the compiler not to optimize it out is tricky, but many cryptographic libraries include that functionality. The c11 standard has a memset_s function with the right semantics, but there are other ways to implement it.

Re: constant time operations, I don't know of any language or system that does this currently. But a while back I was kicking around the idea with a friend and we came to a design that I'm pretty sure would work. Never got around to implementation though; so many projects, so little time.

We can absolutely use types to ensure that our algorithms are constant time, e.g.

https://www.usenix.org/conference/usenixsecurity16/technical...

We can use types to enforce the big-O runtime of our functions too, e.g. ensuring that a mergesort implementation runs in O(nlogn) steps: https://www.twanvl.nl/blog/agda/sorting

I have no idea about doing these things in Java/C/C++/C# though; anything we try to enforce can be trivially broken by `NULL` :(

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