[Cryptography] Secure erasure

[Patrick Pelletier]

On 9/9/16 5:28 PM, John Denker wrote:
> The way forward is to stop oversimplifying.  Start by asking What's
> Your Threat Model.  The real threats come from verrrry far outside
> the domain of specification for ordinary computer languages:  cold
> boot, attackers with root privilege, NSA "tailoring" (i.e. subversion)
> of the firmware in the flash controller, tempest, et cetera.

I would argue the opposite: the most likely threat comes from a 
Heartbleed-style vulnerability, where your own process gets tricked into 
revealing the contents of its own memory.  In that sort of a threat 
model, the hardware doesn't matter, swap doesn't matter, caches don't 
matter.  All that matters is what's visible in the process's address 
space.  This is the sort of threat that the original question in this 
thread can defend against, by zeroing memory.

--Patrick