Matrix Ciphers - Introduction to Cryptography with Java Applets - page 159

the exercises using only knowledge of the modulus, the block size, and the plain-
text-ciphertext message pairs. If you are unable to obtain these matrices, state why.

5. Show that if T is a transposition matrix, then the inverse of T is the same as the trans-

pose of T .

6. Encipher and decipher the following messages:

a. GREY LADY DOWN

b. WHERE EAGLES DARE

TOKYO IN FLAMES
Pad with the letter X if necessary. Use the transposition matrix

c.

0001000
0100000
1000000
0000100
0000010
0000001
0010000

7. Repeat the previous exercise, but first encrypt with matrix A , given by

20 15 3 1 5
4 3 643
3 8 13 10 8
12 15 4 3 2
56789

then with the transposition matrix, then again with matrix A .

8. Implement a matrix cipher program by adding a matrixEncipher() method and a

matrixDecipher() method to the Ciphers class.