Comment 3 for bug 1384463

This is a rst file: https://github.com/pyca/cryptography/blob/master/docs/security.rst

I assume the issue is that x is actually `x.encode("utf-8")`:

>>>> x = u'known exploit in the wild, for example – the time between advance notification'
>>>> len(x)
78
>>>> len(x.encode("utf-8"))
80