Appendix G: Exercises - Codes: The Guide to Secrecy from Ancient to Modern Times - page 569

3.25. Assuming the bitstring found as plaintext in Exercise 3.24 is to be inter-
preted as a concatenation of bitstrings of length five, each corresponding
to an English letter whose numerical equivalent in decimal is given by
Table 1.3 on page 11, find the English text equivalent of that bitstring.
In Exercises 3.26-3.29, assume that n =26 in the Vigenere cipher described
on page 153, and use the given key, as well as the values of r and s given
in each case, to decrypt the ciphertext. Use the numerical equivalents from
Table 1.3 on page 11 to find the English text.
3.26. Let r =3, s = 31 and k =(3 , 7 , 9).
c = WONIPAVAAHHLWPXQAXWYDWORVOJWYNG .
This is a quote from Tertullian (circa 160-225 AD), known formally as
Quintus Septimus Florens Tertullianus . He was a Carthagian-born Latin
church father. The quote is taken from “Apologeticus” (circa 197 AD) .
3.27. Let r =5, s = 26, and k = (11 , 13 , 17 , 19 , 20).
c = LALGODRUECQRZLUYRRKFJQVTNS .
This is a quote from Johann Wolfgang Von Goethe (1749-1832) , a German
poet, dramatist, and philosopher. The quote is taken from Act 1, Scene 1
of “Iphigenie auf Tarris” (1787) .
3.28. Let r =7, s = 34, and k =(1 , 2 , 4 , 6 , 8 , 10 , 12).
c = TKPKVMQJUELZSQOFANWGUMNRKDODCGXXII .
This is a quote from Confucius (551-479 BC) who was a Chinese
sage/philosopher.
3.29. Let r =5, s = 15, and k =(1 , 17 , 18 , 20 , 21).
c = OFLBDOXAHZYTWMN .
This is a quote from Pittacus of Lesbos (650-570 BC) , who was one of
the seven sages of ancient Greece.
In Exercises 3.30-3.33, assume n =26 in the autokey Vigenere cipher
described on page 154, and using the given values of r , s , and k in each
case decipher the cryptograms. As usual, employ Table 1.3 for numerical
equivalents.
3.30. Let r =2, s = 16, and k =38= k 1 k 2 .
c = XVMNXEFXAGYFNWTH .
This is the title of a topic by Ralph Nader (1934-), an American consumer
protectionist.