[Python-Dev] Hashing proposal: 64-bit hash

[Frank Sievertsen]

>
> The point is not the length of the string, but the size of string 
> space for inspection. To search for a string with a specified 64-bit 
> hash to iterate over 2 ** 64 strings. Spending on a single string scan 
> 1 nanosecond (a very optimistic estimate), it would take 2 ** 64 / 1e9 
> / (3600 * 24 * 365.25) = 585 years. For the attack we need to find 
> 1000 such strings -- more than half a million years. For 32-bit hash 
> would need only an hour.
>

With meet-in-the-middle and some other tricks it's possible to generate 
25,000 64-bit-collisions per hour using an older desktop-cpu and 4gb ram.

H_dypmRNWgOxiaaG
A_ceO8B4Q2eKfabi
S_kpgdB3tUFJiaae
H_dypmRNWgOxiaaG
D_FYzdys3H8qbaba
0_pOwRq15h8vbabO
S_kpgdB3tUFJiaae
__mdKp1GvI_fcaaM
6_U3_B0pJT1UsaaW
4_1GnK9BmLj9naa5
__X7hMeAOpACdaaw
B_7pm.T62SiLlaai
I_HSdl0axd8tmaae
T_Dv3LwayACpdaaO

Frank