The New Sudoku Players' Forum

[Bigtone53]

A relevant cipher for those who like fair play and a relatively basic sudoku technique

CAOZZ MEORX DFINP MMZ

[Bigtone53]

I can understand that not many people might be interested in ciphers but I did try and make it easy. The fair play reference was to the Playfair cipher, which is explained here

http://rumkin.com/tools/cipher/playfair.php

[MCC]

I've worked this backwards and got:

BEPYWPDPSWAIHOOLPW

[Bigtone53]

I've worked this backwards and got:

BEPYWPDPSWAIHOOLPW

You need to find a codeword to start the playfair grid. If for instance the codeword was bigtone, the 5x5 grid would be

B I G T O
N E A C D
F H K L M
P Q R S U
V W X Y Z

The original posting should assist.

[r.e.s.]

A relevant cipher for those who like fair play and a relatively basic sudoku technique

CAOZZ MEORX DFINP MMZ

Hi Bigtone53,

It may turn out that someone can guess the Playfair keyword or part of the plaintext for this ciphertext, but otherwise it seems unlikely that such a short message will be decrypted. It was considered noteworthy when a private in the US Army Signal Corp deciphered a 30-letter message of this kind in 1936 -- a feat described in Ref.2 <here> -- and yours is much shorter than that.

Edits: Reworded a reference to cribs.

[Bigtone53]

Thanks r.e.s. for the reference. I do understand but I thought that as

a) I have indicated that the keyword is sudoku-related, and

b) that the message is relevant,

this would assist those interested.

The big c) is that there are Playfair crackers on the net if you can take an educated guess about what the message may be about. Messages with repeated letters cannot always be encoded and the convention is to leave one out when encoding, as in Hapy New Year.

[r.e.s.]

Ok, I used the software at your given link to solve it by guessing different keywords.

Rather than reveal your plaintext message, here's an encrypted message using that plaintext message as the "keyword":
AWTAC BTSBT NLBWE SONWX

[udosuk]

Is the keyword one of the following:

single, pair, triple, quad, xwing, swordfish

[Bigtone53]

Is the keyword one of the following:

single, pair, triple, quad, xwing, swordfish

yes

[MCC]

I finally got it after making a complete hash of the decryption method.

And for r.e.s.

Deck the halls with boughs of holly,
Fa la la la la, la la la la.
Tis the season to be jolly,
Fa la la la la, la la la la.

Don we now our gay apparel,
Fa la la, la la la, la la la.
Troll the ancient Yule tide carol,
Fa la la la la, la la la la.

See the blazing Yule before us,
Fa la la la la, la la la la.
Strike the harp and join the chorus.
Fa la la la la, la la la la.

Follow me in merry measure,
Fa la la la la, la la la la.
While I tell of Yule tide treasure,
Fa la la la la, la la la la.

Fast away the old year passes,
Fa la la la la, la la la la.
Hail the new, ye lads and lasses,
Fa la la la la, la la la la.

Sing we joyous, all together,
Fa la la la la, la la la la.
Heedless of the wind and weather,
Fa la la la la, la la la la.

MCC

[r.e.s.]

Hi MCC,

I just noticed a funny little coincidence ...

When encrypting the word JOLLY, before applying the Playfair grid, I used the suggested conventions of replacing LL --> L and J --> I, giving IOLY.

Now in fact the word JOLLY actually derives from the word YULE, which (according to my dictionary) was IOL in Old Norse -- so of course 'tis the season to be IOLY!

[MCC]

Fact is often stranger than fiction

J.

In Roman numerals, [j] replaced the last [i] in a number:

i, ij, iij, iv, v, vj, vij, viij, viiij or ix, x.


MCC

[udosuk]

Here is Bigtone53's message, encrypted with a different keyword:

Code: Select all

EFLKH KILPO LTZDL RKH

The keyword is a certain Aussie cricketer, who just missed out on a world record yesterday...

[r.e.s.]

Hi udosuk,

Not knowing the first thing about cricket, I still managed to figure out by trial-and-error that Adam Gilchrist is the keyword (Wikipedia is great).

[udosuk]

Yes, I didn't intend to make it a hard riddle... Glad you learned something about our cricket players...

Hope you enjoy the process of decryption this time...