Below is a three-dimensional picture of the character array
pas
wor
dbc
efg
hij
klm
nqt
uvx
yz_
0
\
\
\
n------q------t
|\ \ \
| e------f------g
u |\ \ \
|\| p------a------s------------1
| h | | |
y |\| | |
\| w------o------r
k | | |
\| | |
d------b------c
|
|
|
|
2
Does the picture help you formulate a 3-d analogue of the Playfair cipher for
encoding “All is discovered flee” from the triples
alx isd isc ove red fle ex_ ? Those triples again are
alx
isd
isc
ove
red
fle
ex_
On 2/19/2011 6:40 AM, Kip Murray wrote:
> The Playfair cipher http://en.wikipedia.org/wiki/Playfair_cipher is based on
> a 5
> by 5 character array that treats i and j as equivalent:
>
> paswo
> rdbce
> fghik
> lmnqt
> uvxyz
>
> To encode “All is discovered flee” you replace pairs of letters
> al li sd is co ve re df le ex with pairs diagonally opposite, one to the
> right,
> or one below (wrapping) from the table, getting
>
> pm qf ab hw ew zd dr rg tr bz
>
> Your mission, should you decide to accept it, is to write j code for
> enciphering
> and deciphering, given the five by five table. That’s the easy part. The
> hard
> part is to design and implement an analogous cipher that uses the 3 by 3 by 3
> character array below to replace triples of letters alx _is _di sco ver ed_
> fle ex_
>
> pas
> wor
> dbc
>
> efg
> hij
> klm
>
> nqt
> uvx
> yz_
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
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For information about J forums see http://www.jsoftware.com/forums.htm
