<s>
Red	B-Algorithm
Pike	I-Algorithm
is	O
a	O
classified	O
United	O
Kingdom	O
government	O
encryption	O
algorithm	O
,	O
proposed	O
for	O
use	O
by	O
the	O
National	O
Health	O
Service	O
by	O
GCHQ	O
,	O
but	O
designed	O
for	O
a	O
"	O
broad	O
range	O
of	O
applications	O
in	O
the	O
British	O
government	O
"	O
.	O
</s>
<s>
Little	O
is	O
publicly	O
known	O
about	O
Red	B-Algorithm
Pike	I-Algorithm
,	O
except	O
that	O
it	O
is	O
a	O
block	O
cipher	O
with	O
a	O
64-bit	O
block	O
size	O
and	O
64-bit	O
key	O
length	O
.	O
</s>
<s>
According	O
to	O
the	O
academic	O
study	O
of	O
the	O
cipher	O
cited	O
below	O
and	O
quoted	O
in	O
a	O
paper	O
by	O
Ross	O
Anderson	O
and	O
Markus	O
Kuhn	O
,	O
it	O
"	O
uses	O
the	O
same	O
basic	O
operations	O
as	O
RC5	B-Algorithm
"	O
(	O
add	O
,	O
XOR	O
,	O
and	O
left	O
shift	O
)	O
and	O
"	O
has	O
no	O
look-up	O
tables	O
,	O
virtually	O
no	O
key	O
schedule	O
and	O
requires	O
only	O
five	O
lines	O
of	O
code	O
"	O
;	O
"	O
the	O
influence	O
of	O
each	O
key	O
bit	O
quickly	O
cascades	O
"	O
and	O
"	O
each	O
encryption	O
involves	O
of	O
the	O
order	O
of	O
100	O
operations	O
"	O
.	O
</s>
<s>
Red	B-Algorithm
Pike	I-Algorithm
is	O
available	O
to	O
approved	O
British	O
government	O
contractors	O
in	O
software	O
form	O
,	O
for	O
use	O
in	O
confidential	O
(	O
not	O
secret	O
)	O
government	O
communication	O
systems	O
.	O
</s>
<s>
GCHQ	O
also	O
designed	O
the	O
Rambutan	B-Algorithm
cryptosystem	O
for	O
the	O
same	O
segment	O
.	O
</s>
<s>
Given	O
that	O
Red	B-Algorithm
Pike	I-Algorithm
is	O
a	O
British	O
encryption	O
algorithm	O
,	O
its	O
name	O
likely	O
refers	O
to	O
a	O
particular	O
fell	O
in	O
the	O
western	O
English	O
Lake	O
District	O
.	O
</s>
<s>
In	O
February	O
2014	O
,	O
the	O
supposed	O
source	O
code	O
for	O
Red	B-Algorithm
Pike	I-Algorithm
was	O
posted	O
as	O
follows	O
to	O
the	O
Cypherpunk	O
mailing	O
list	O
.	O
</s>
