[Cryptography] Is it mathematically provably impossible to construct a mechanism to test for back doors in programs?

[Bear]

On Tue, 2014-06-03 at 13:03 -0400, Phillip Hallam-Baker wrote:

> Now obviously there is a theoretical possibility that they all might
> collude and default but it is pretty unlikely that they would and it
> would certainly be noticed. I think that is far better in practice
> than the BitCoin block chain with its known vulnerability to unwinding
> transactions.

No, it isn't a theoretical possibility.  It *IS* the threat model, 
because we're now talking about adversaries with the capability to 
*FORCE* that collusion regardless of whether the entities involved
are willing to collude.  

Basically, what you're betting on is that someone on your list is 
both willing to go to jail and able to defeat professionals who 
have had time to prepare their tactics around the possibility and
who can choose their time and place of intervention to limit the
ability of any such willing person to get the warning out.

			Bear