<s>
The	O
Beaufort	B-Algorithm
cipher	I-Algorithm
,	O
created	O
by	O
Sir	O
Francis	O
Beaufort	O
,	O
is	O
a	O
substitution	O
cipher	O
similar	O
to	O
the	O
Vigenère	B-Algorithm
cipher	I-Algorithm
,	O
with	O
a	O
slightly	O
modified	O
enciphering	O
mechanism	O
and	O
tableau	B-Algorithm
.	O
</s>
<s>
The	O
Beaufort	B-Algorithm
cipher	I-Algorithm
is	O
based	O
on	O
the	O
Beaufort	O
square	O
which	O
is	O
essentially	O
the	O
same	O
as	O
a	O
Vigenère	B-Algorithm
square	I-Algorithm
but	O
in	O
reverse	O
order	O
starting	O
with	O
the	O
letter	O
"	O
Z	O
"	O
in	O
the	O
first	O
row	O
,	O
where	O
the	O
first	O
row	O
and	O
the	O
last	O
column	O
serve	O
the	O
same	O
purpose	O
.	O
</s>
<s>
To	O
encrypt	O
,	O
first	O
choose	O
the	O
plaintext	O
character	O
from	O
the	O
top	O
row	O
of	O
the	O
tableau	B-Algorithm
;	O
call	O
this	O
column	O
P	O
.	O
Secondly	O
,	O
travel	O
down	O
column	O
P	O
to	O
the	O
corresponding	O
key	O
letter	O
K	O
.	O
Finally	O
,	O
move	O
directly	O
left	O
from	O
the	O
key	O
letter	O
to	O
the	O
left	O
edge	O
of	O
the	O
tableau	B-Algorithm
,	O
the	O
ciphertext	O
encryption	O
of	O
plaintext	O
P	O
with	O
key	O
K	O
will	O
be	O
there	O
.	O
</s>
<s>
travel	O
to	O
the	O
left	O
edge	O
of	O
the	O
tableau	B-Algorithm
to	O
find	O
the	O
ciphertext	O
letter	O
(	O
"	O
K	O
"	O
in	O
this	O
case	O
)	O
.	O
</s>
<s>
Unlike	O
the	O
otherwise	O
very	O
similar	O
Vigenère	B-Algorithm
cipher	I-Algorithm
,	O
the	O
Beaufort	B-Algorithm
cipher	I-Algorithm
is	O
a	O
reciprocal	O
cipher	O
,	O
that	O
is	O
,	O
decryption	O
and	O
encryption	O
algorithms	O
are	O
the	O
same	O
.	O
</s>
<s>
The	O
Beaufort	B-Algorithm
cipher	I-Algorithm
can	O
be	O
described	O
algebraically	O
.	O
</s>
<s>
Due	O
to	O
the	O
similarities	O
between	O
the	O
Beaufort	B-Algorithm
cipher	I-Algorithm
and	O
the	O
Vigenère	B-Algorithm
cipher	I-Algorithm
it	O
is	O
possible	O
,	O
after	O
applying	O
a	O
transformation	O
,	O
to	O
solve	O
it	O
as	O
a	O
Vigenère	B-Algorithm
cipher	I-Algorithm
.	O
</s>
<s>
an	O
Atbash-transformation	O
)	O
it	O
can	O
be	O
solved	O
like	O
a	O
Vigenère	B-Algorithm
cipher	I-Algorithm
.	O
</s>
<s>
The	O
Beaufort	B-Algorithm
cipher	I-Algorithm
should	O
not	O
be	O
confused	O
with	O
the	O
"	O
variant	O
Beaufort	O
"	O
cipher	O
.	O
</s>
<s>
In	O
variant	O
Beaufort	O
,	O
encryption	O
is	O
performed	O
by	O
performing	O
the	O
decryption	O
step	O
of	O
the	O
standard	O
Vigenère	B-Algorithm
cipher	I-Algorithm
,	O
and	O
likewise	O
decryption	O
is	O
performed	O
by	O
using	O
Vigenère	O
encryption	O
.	O
</s>
