Azed 2164

[professorplum13]

8d Grand aim, when about to follow curriculum level (8, 2 words) ?E???A?E
16d Act of awarding first, one bagged by night bird (8) B????????

Not sure how to use the "Playfair breaker"
For 5a I think the clued answer is OMASAL, letters in my grid so far are TP??S? - assume that will be TPS?S because of the 2 "A"s in omasal?

tried putting OMASAL in the "plain text" box , but what do I enter in the cipher box?

[dr b]

key stage

best ow(a)l

[dr b]

if you're using quinapalus put TPSK in cipher box, OMAL in plain text. You need to know the whole cipher text, can use ?'s for plain text

enter character strings that you know from ciphertext and corresponding strings from plaintext.

[dr b]

once you have the keyword

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

to encode/decode

[professorplum13]

Thank you dr b. I shall plod on!

[Helveticus]

Prof. Plum: Plaintext A will not always encipher as S, since Playfair encodes letter *pairs* (digraphs). If you have enough plaintext and ciphertext, it is not too difficult to work out the keyword. It is a good idea to use Excel, as you can then shuffle the rows and/or columns easily without making mistakes. Start by taking a plaintext/ciphertext digraph pair where all 4 letters are known and the plaintext/ciphertext digraphs share a letter (e.g. XY => YZ). In this case, you know that X, Y and Z are all in the same row (or same column) and that they are in the order XYZ with nothing in between (though possibly "wrapping around" to the beginning of the row (or column). Take the next plaintext/ciphertext pair which shares as many letters as possible as the ones in your grid. You should be able to place more letters somewhere which does not violate the coding rules, but you may have to re-order the rows and/or columns to make sure that all the plaintext digraphs so far encode correctly. Carry on in this way, adding more letters to your grid and shuffling the rows and/or columns if necessary until your grid is full. At this point you can cycle the rows and/or columns to get the keyword (remember: letters which are *not* in the keyword appear in alphabetical order in the grid). Good luck!