<s>
RainbowCrack	B-General_Concept
is	O
a	O
computer	O
program	O
which	O
generates	O
rainbow	B-Algorithm
tables	I-Algorithm
to	O
be	O
used	O
in	O
password	O
cracking	O
.	O
</s>
<s>
RainbowCrack	B-General_Concept
differs	O
from	O
"	O
conventional	O
"	O
brute	O
force	O
crackers	O
in	O
that	O
it	O
uses	O
large	O
pre-computed	O
tables	O
called	O
rainbow	B-Algorithm
tables	I-Algorithm
to	O
reduce	O
the	O
length	O
of	O
time	O
needed	O
to	O
crack	O
a	O
password	O
drastically	O
.	O
</s>
<s>
RainbowCrack	B-General_Concept
was	O
developed	O
by	O
Zhu	O
Shuanglei	O
,	O
and	O
implements	O
an	O
improved	O
time	O
–	O
memory	O
tradeoff	O
cryptanalysis	O
attack	O
which	O
originated	O
in	O
Philippe	O
Oechslin	O
's	O
Ophcrack	B-Application
.	O
</s>
<s>
Some	O
organizations	O
have	O
made	O
RainbowCrack	B-General_Concept
's	O
rainbow	B-Algorithm
tables	I-Algorithm
available	O
free	O
over	O
the	O
internet	O
.	O
</s>
