[Cryptography] What do we mean by Secure?

[Richard Outerbridge]

On 2015-02-09 (40), at 23:06:48, alex at alten.org wrote:
> 
> Quoting Kent Borg <kentborg at borg.org>:
> 
>> On 02/09/2015 02:08 AM, alex at alten.org wrote:
>>> For myself security is just another engineering domain, like software
>>> or electrical engineering.

>> [….]

> 
> No engineering discipline is perfect, think of crashed airplanes,
> sunk boats, or collapsed bridges.

The Romans, for THE example of engineers, are said to have made
their architects stand below their arches as the first loads passed
overhead.

> Your rightly point out that Security engineering has differences
> from other engineering disciplines.
> 
> It usually has to prove a negative, which is a key difference.

I think I was taught that was logically, literally, impossible.
Wasn’t that how Turing’s Bombe worked?
__outer