[issue13703] Hash collision security issue

[STINNER Victor]

STINNER Victor <victor.stinner at haypocalc.com> added the comment:

> At least for Python 2.x hash(str) and hash(unicode) have to yield
> the same result for ASCII only strings. 

Ah yes, I forgot Python 2: I wrote my patch for Python 3.3. The two hash functions should be modified to be randomized.

> hash("") should always return 0

Ok, I can add a special case. Antoine told me that hash("") gives prefix ^ suffix, which is too much information for the attacker :-)

> for small strings we could use a different seed
> than for larger strings

Why? The attack doesn't work with short strings? What do you call a "short string"?

----------

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue13703>
_______________________________________