<s>
In	O
cryptography	O
,	O
the	O
EFF	B-Algorithm
DES	I-Algorithm
cracker	I-Algorithm
(	O
nicknamed	O
"	O
Deep	B-Algorithm
Crack	I-Algorithm
"	O
)	O
is	O
a	O
machine	O
built	O
by	O
the	O
Electronic	O
Frontier	O
Foundation	O
(	O
EFF	O
)	O
in	O
1998	O
,	O
to	O
perform	O
a	O
brute	O
force	O
search	O
of	O
the	O
Data	B-Algorithm
Encryption	I-Algorithm
Standard	I-Algorithm
(	O
DES	B-Algorithm
)	O
cipher	O
's	O
key	O
space	O
–	O
that	O
is	O
,	O
to	O
decrypt	O
an	O
encrypted	O
message	O
by	O
trying	O
every	O
possible	O
key	O
.	O
</s>
<s>
The	O
aim	O
in	O
doing	O
this	O
was	O
to	O
prove	O
that	O
the	O
key	O
size	O
of	O
DES	B-Algorithm
was	O
not	O
sufficient	O
to	O
be	O
secure	O
.	O
</s>
<s>
Detailed	O
technical	O
data	O
of	O
this	O
machine	O
,	O
including	O
block	B-Application
diagrams	I-Application
,	O
circuit	B-Application
schematics	I-Application
,	O
VHDL	B-Language
source	O
code	O
of	O
the	O
custom	O
chips	O
and	O
its	O
emulator	B-Application
,	O
have	O
all	O
been	O
published	O
in	O
the	O
book	O
Cracking	O
DES	B-Algorithm
.	O
</s>
<s>
Machine-readable	O
metadata	O
is	O
provided	O
to	O
facilitate	O
the	O
transcription	O
of	O
the	O
code	O
into	O
a	O
computer	O
via	O
OCR	B-Application
by	O
readers	O
.	O
</s>
<s>
DES	B-Algorithm
uses	O
a	O
56-bit	O
key	O
,	O
meaning	O
that	O
there	O
are	O
256	O
possible	O
keys	O
under	O
which	O
a	O
message	O
can	O
be	O
encrypted	O
.	O
</s>
<s>
One	O
of	O
the	O
major	O
criticisms	O
of	O
DES	B-Algorithm
,	O
when	O
proposed	O
in	O
1975	O
,	O
was	O
that	O
the	O
key	O
size	O
was	O
too	O
short	O
.	O
</s>
<s>
DES	B-Algorithm
was	O
a	O
federal	O
standard	O
,	O
and	O
the	O
US	O
government	O
encouraged	O
the	O
use	O
of	O
DES	B-Algorithm
for	O
all	O
non-classified	O
data	O
.	O
</s>
<s>
RSA	O
Security	O
wished	O
to	O
demonstrate	O
that	O
DES	B-Algorithm
's	O
key	O
length	O
was	O
not	O
enough	O
to	O
ensure	O
security	O
,	O
so	O
they	O
set	O
up	O
the	O
DES	B-Algorithm
Challenges	O
in	O
1997	O
,	O
offering	O
a	O
monetary	O
prize	O
.	O
</s>
<s>
The	O
first	O
DES	B-Algorithm
Challenge	O
was	O
solved	O
in	O
96	O
days	O
by	O
the	O
DESCHALL	B-Algorithm
Project	I-Algorithm
led	O
by	O
Rocke	O
Verser	O
in	O
Loveland	O
,	O
Colorado	O
.	O
</s>
<s>
RSA	O
Security	O
set	O
up	O
DES	B-Algorithm
Challenge	O
II-1	O
,	O
which	O
was	O
solved	O
by	O
distributed.net	O
in	O
39	O
days	O
in	O
January	O
and	O
February	O
1998	O
.	O
</s>
<s>
In	O
1998	O
,	O
the	O
EFF	O
built	O
Deep	B-Algorithm
Crack	I-Algorithm
(	O
named	O
in	O
reference	O
to	O
IBM	O
's	O
Deep	B-General_Concept
Blue	I-General_Concept
chess	O
computer	O
)	O
for	O
less	O
than	O
$	O
250,000	O
.	O
</s>
<s>
In	O
response	O
to	O
DES	B-Algorithm
Challenge	O
II-2	O
,	O
on	O
July	O
15	O
,	O
1998	O
,	O
Deep	B-Algorithm
Crack	I-Algorithm
decrypted	O
a	O
DES-encrypted	O
message	O
after	O
only	O
56	O
hours	O
of	O
work	O
,	O
winning	O
$	O
10,000	O
.	O
</s>
<s>
The	O
brute	O
force	O
attack	O
showed	O
that	O
cracking	O
DES	B-Algorithm
was	O
actually	O
a	O
very	O
practical	O
proposition	O
.	O
</s>
<s>
Most	O
governments	O
and	O
large	O
corporations	O
could	O
reasonably	O
build	O
a	O
machine	O
like	O
Deep	B-Algorithm
Crack	I-Algorithm
.	O
</s>
<s>
Six	O
months	O
later	O
,	O
in	O
response	O
to	O
RSA	O
Security	O
's	O
DES	B-Algorithm
Challenge	O
III	O
,	O
and	O
in	O
collaboration	O
with	O
distributed.net,	O
the	O
EFF	O
used	O
Deep	B-Algorithm
Crack	I-Algorithm
to	O
decrypt	O
another	O
DES-encrypted	O
message	O
,	O
winning	O
another	O
$	O
10,000	O
.	O
</s>
<s>
In	O
October	O
of	O
that	O
year	O
,	O
DES	B-Algorithm
was	O
reaffirmed	O
as	O
a	O
federal	O
standard	O
,	O
but	O
this	O
time	O
the	O
standard	O
recommended	O
Triple	B-Algorithm
DES	I-Algorithm
.	O
</s>
<s>
The	O
small	O
key	O
space	O
of	O
DES	B-Algorithm
and	O
relatively	O
high	O
computational	O
costs	O
of	O
Triple	B-Algorithm
DES	I-Algorithm
resulted	O
in	O
its	O
replacement	O
by	O
AES	B-Algorithm
as	O
a	O
Federal	O
standard	O
,	O
effective	O
May	O
26	O
,	O
2002	O
.	O
</s>
<s>
Deep	B-Algorithm
Crack	I-Algorithm
was	O
designed	O
by	O
Cryptography	O
Research	O
,	O
Inc.	O
,	O
Advanced	O
Wireless	O
Technologies	O
,	O
and	O
the	O
EFF	O
.	O
</s>
<s>
The	O
principal	O
designer	O
was	O
Paul	O
Kocher	O
,	O
president	O
of	O
Cryptography	B-General_Concept
Research	I-General_Concept
.	O
</s>
<s>
Advanced	O
Wireless	O
Technologies	O
built	O
1,856	O
custom	O
ASIC	O
DES	B-Algorithm
chips	O
(	O
called	O
Deep	B-Algorithm
Crack	I-Algorithm
or	O
AWT-4500	B-Algorithm
)	O
,	O
housed	O
on	O
29	O
circuit	O
boards	O
of	O
64	O
chips	O
each	O
.	O
</s>
<s>
The	O
boards	O
were	O
then	O
fitted	O
in	O
six	O
cabinets	O
and	O
mounted	O
in	O
a	O
Sun-4/470	B-Device
chassis	O
.	O
</s>
<s>
In	O
2006	O
,	O
another	O
custom	B-General_Concept
hardware	I-General_Concept
attack	I-General_Concept
machine	O
was	O
designed	O
based	O
on	O
FPGAs	B-Architecture
.	O
</s>
<s>
COPACOBANA	B-General_Concept
(	O
COst-optimized	O
PArallel	O
COdeBreaker	O
)	O
is	O
able	O
to	O
crack	O
DES	B-Algorithm
at	O
considerably	O
lower	O
cost	O
.	O
</s>
<s>
In	O
July	O
2012	O
,	O
security	O
researchers	O
David	O
Hulton	O
and	O
Moxie	O
Marlinspike	O
unveiled	O
a	O
cloud	O
computing	O
tool	O
for	O
breaking	O
the	O
MS-CHAPv2	B-Algorithm
protocol	O
by	O
recovering	O
the	O
protocol	O
's	O
DES	B-Algorithm
encryption	O
keys	O
by	O
brute	O
force	O
.	O
</s>
<s>
This	O
tool	O
effectively	O
allows	O
members	O
of	O
the	O
general	O
public	O
to	O
recover	O
a	O
DES	B-Algorithm
key	O
from	O
a	O
known	O
plaintext	O
–	O
ciphertext	O
pair	O
in	O
about	O
24	O
hours	O
.	O
</s>
