[Python-Dev] hash randomization in 3.3

[Stephen J. Turnbull]

Antoine Pitrou writes:

 > How is it a "false sense of security" at all? It's the same as
 > setting a private secret for e.g. session cookies in Web applications.
 > As long as you don't leak the seed, it's (should be) secure.

That's true.  The problem is, the precondition that you won't leak the
seed is all too often false.  If a user takes advantage of the ability
to set the seed, she can leak it, or a coworker (or a virus) can steal
it from her source or keystroke logging, etc.

And it's not the same, at least not for a highly secure application.
In high-quality security, session keys are generated for each session
(and changed frequently); the user doesn't know them (of course, he
can always find out if he really wants to know, and sometimes that's
necessary -- Hello, Debian OpenSSH maintainer!), and so can't leak
them.