Answer:
1. What is the Delastelle cipher (and a key of "EPSDUCVWYM.ZLKXNBTFGORIJHAQ"): sensible
Additional information:
An example key is: EPSDUCVWYM.ZLKXNBTFGORIJHAQ We then make three squares from this: square 1 square 2 square 3 1 2 3 1 2 3 1 2 3 1 E P S 1 M . Z 1 F G O 2 D U C 2 L K X 2 R I J 3 V W Y 3 N B T 3 H A Q If we take a plain text message of "THIS IS A TEST", we locate the text in the squares defined above: THIS IS A TEST -------------- T - 233 H - 331 I - 322 S - 113 I - 322 S - 113 A - 332 T - 233 E - 111 S - 113 T - 233 Next we would order as: THISISATEST ----------- 23333132211 33221133322 33111113233 And we would read the code in a horizontal way to give: 233 333 321 321 311 111 331 233 232 123 123 And then substitute back the letters on the grid: 233 333 321 321 311 111 331 233 232 123 123 T Q R R F E H T B C C
Ans: QUWADAIV