From: Tim Roberts <timr@...>
Date: 2012-03-28T12:36:08+09:00
Subject: Re: Write to kernel buffer?

Robert Klemme <lists@ruby-forum.com> wrote:
>
>I think there's a simpler way to achieve wiping:
>
># read
>@password = ...
>
># wipe after 2 secs
>Thread.new do
>  sleep 2
>  @password.replace("#" * @password.length)
>end

In a garbage collecting system, how could you possibly assume that the
location of "password" will not have changed in the interim?  You don't
have enough visibility into the "innards" to assume that.

Indeed, I believe this is an unsolvable problem in a language like Ruby.
You'd have to do this all in C.
-- 
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.