[Typo3-dev] thougts of TYPO3 imagefunction and short MD5 Hash

[Daniel Pötzinger]

Hello

I know some time ago kasper answerd if the short md5 hash is long enough 
  for storing cashed images, right?

Now I have a client how manage a site with much images, and he had the 
problem that in a imagegallerie sometimes a wrong images is displayed.

So I make this simple stochastic thougts.
The ShortMd5 Hash consits of 10 chars (0-9 a-z)
there are 35^10 (ca. 3 quadrillion!!) possible places in the "Hash-table"

But TYPO3 dont look for collision, right?

the "rule of thumb" is that the if we had allready "root of hashplaces" 
items in the hashtable (in this case: sqrt(35^10) = 52 Millions) the 
probability of an collision is bigger than to find a free position..

52Millions sounds much but
- the algorithm did not distribut similar over the whole hashplaces and
-there is no "collision detecting"  (or is there collisiondection in new 
TYPO3 Version?)

I think this is the reason why the client gets wrong images in his 
gallerie. Please correct me if I am wrong.