Label polymorphism

[Ben Shapero]

Could label polymorphism be explained again?  Is it really just saying that labels can be put on any time of data/variable/function?  

[Eve]

I think label polymorphism enables functions to be called regardless of the labels of the arguments. As such, code does not always have to be written with a specific security policy in mind, which is good when you are trying to write reusable code (libraries, for example).

[dm-list-c...@scs.stanford.edu]

At Sat, 9 Feb 2013 09:02:58 -0800 (PST),

Eve wrote:
>
> I think label polymorphism enables functions to be called regardless of the
> labels of the arguments. As such, code does not always have to be written with
> a specific security policy in mind, which is good when you are trying to write
> reusable code (libraries, for example).

Exactly. So for example you could have a simple function whose return
value always has the same label as its input. That same function can
be called on differently labeled data, and only one copy of the code
is required. Fig. 7 in the paper shows a more complicated example,
where internally the code accumulates more restrictions and then
strips them off, yielding the same label as the input. This works
regardless of what the input label was.

David