<s>
In	O
cryptography	O
,	O
a	O
custom	B-General_Concept
hardware	I-General_Concept
attack	I-General_Concept
uses	O
specifically	O
designed	O
application-specific	O
integrated	O
circuits	O
(	O
ASIC	O
)	O
to	O
decipher	O
encrypted	O
messages	O
.	O
</s>
<s>
Computers	O
can	O
perform	O
these	O
calculations	O
at	O
a	O
rate	O
of	O
millions	O
per	O
second	O
,	O
and	O
thousands	O
of	O
computers	O
can	O
be	O
harnessed	O
together	O
in	O
a	O
distributed	B-Architecture
computing	I-Architecture
network	O
.	O
</s>
<s>
The	O
primary	O
limitations	O
on	O
this	O
method	O
are	O
the	O
cost	O
of	O
chip	O
design	O
,	O
IC	B-Architecture
fabrication	I-Architecture
,	O
floor	O
space	O
,	O
electric	O
power	O
and	O
thermal	O
dissipation	O
.	O
</s>
<s>
An	O
alternative	O
approach	O
is	O
to	O
use	O
FPGAs	B-Architecture
(	O
field-programmable	B-Architecture
gate	I-Architecture
arrays	I-Architecture
)	O
;	O
these	O
are	O
slower	O
and	O
more	O
expensive	O
per	O
gate	O
,	O
but	O
can	O
be	O
reprogrammed	O
for	O
different	O
problems	O
.	O
</s>
<s>
(	O
Cost-Optimized	O
Parallel	O
COde	O
Breaker	O
)	O
is	O
one	O
such	O
machine	O
,	O
consisting	O
of	O
120	O
FPGAs	B-Architecture
of	O
type	O
Xilinx	O
Spartan3-1000	O
which	O
run	O
in	O
parallel	O
.	O
</s>
<s>
The	O
earliest	O
custom	B-General_Concept
hardware	I-General_Concept
attack	I-General_Concept
may	O
have	O
been	O
the	O
Bombe	B-Device
used	O
to	O
recover	O
Enigma	O
machine	O
keys	O
in	O
World	O
War	O
II	O
.	O
</s>
<s>
In	O
1998	O
,	O
a	O
custom	B-General_Concept
hardware	I-General_Concept
attack	I-General_Concept
was	O
mounted	O
against	O
the	O
Data	B-Algorithm
Encryption	I-Algorithm
Standard	I-Algorithm
cipher	O
by	O
the	O
Electronic	O
Frontier	O
Foundation	O
.	O
</s>
<s>
Their	O
"	O
Deep	B-Algorithm
Crack	I-Algorithm
"	O
machine	O
cost	O
U.S.	O
$	O
250,000	O
to	O
build	O
and	O
decrypted	O
the	O
DES	B-Algorithm
Challenge	O
II-2	O
test	O
message	O
after	O
56	O
hours	O
of	O
work	O
.	O
</s>
<s>
The	O
only	O
other	O
confirmed	O
DES	B-Algorithm
cracker	I-Algorithm
was	O
the	O
machine	O
(	O
Cost-Optimized	O
PArallel	O
COde	O
Breaker	O
)	O
built	O
in	O
2006	O
.	O
</s>
<s>
Unlike	O
Deep	B-Algorithm
Crack	I-Algorithm
,	O
COPACOBANA	B-General_Concept
consists	O
of	O
commercially	O
available	O
FPGAs	B-Architecture
(	O
reconfigurable	O
logic	O
gates	O
)	O
.	O
</s>
<s>
COPACOBANA	B-General_Concept
costs	O
about	O
$	O
10,000	O
to	O
build	O
and	O
will	O
recover	O
a	O
DES	B-Algorithm
key	O
in	O
under	O
6.4	O
days	O
on	O
average	O
.	O
</s>
<s>
Since	O
2007	O
,	O
SciEngines	B-Device
GmbH	I-Device
,	O
a	O
spin-off	O
company	O
of	O
the	O
two	O
project	O
partners	O
of	O
COPACOBANA	B-General_Concept
has	O
enhanced	O
and	O
developed	O
successors	O
of	O
COPACOBANA	B-General_Concept
.	O
</s>
<s>
In	O
2008	O
their	O
COPACOBANA	B-General_Concept
RIVYERA	O
reduced	O
the	O
time	O
to	O
break	O
DES	B-Algorithm
to	O
the	O
current	O
record	O
of	O
less	O
than	O
one	O
day	O
,	O
using	O
128	O
Spartan-3	O
5000	O
's	O
.	O
</s>
<s>
It	O
is	O
generally	O
believed	O
that	O
large	O
government	O
code	O
breaking	O
organizations	O
,	O
such	O
as	O
the	O
U.S.	O
National	O
Security	O
Agency	O
,	O
make	O
extensive	O
use	O
of	O
custom	B-General_Concept
hardware	I-General_Concept
attacks	I-General_Concept
,	O
but	O
no	O
examples	O
have	O
been	O
declassified	O
.	O
</s>
