Fixed-width integers

[viluon]

Description
Fixed-width integer types.

Alternatives considered
N/A

Additional context
Efficient variable-width encodings are a great default. Unfortunately, they leak value information via message size, which is not protected by encryption. It would be nice if users could opt into fixed width representations to mitigate security risks.

[stepchowfun]

That's an interesting callout. If you need a workaround today, you could store fixed-width integers as Bytes, but it would be at the expense of ergonomics.