Errata for T. Barr, Invitation to Cryptology, Prentice Hall, 2002
 

page 18:  In the last full line, "up 3, down 5, down 3 up 4, down 1" should read "up 3, down 5, down 2, up 4, down 1".  The ups and downs refer to the direction in which to traverse the respective columns of the array of words.

page 19: In the first line of displayed ciphertext beginning "YOU MARCHED THE IS...", the word OR should be OF.

pages 36-37:  In the telegram of Exercise 18, insert the word JULY between CAMERON and 15 and DC between SIMON and WASHINGTON.  In Exercise 22(c), the third group of ciphertext letters should be LOANE.

page 45:  The last sentence of the paragraph beginning "A permutation of n ordered .. .", should read, "In more practical terms, you can see that the table for q is obtained from that for p by switching the rows of the table for p and then sorting the colums by the entries on the top row."

page 47:  Part b of exercise 6 should read, "By looking at two similar plaintexts such as TEST and PEST, show that P-1(s-1(P(s(x)))) is not a substitution.

page 78:  In the letter frequency chart in the middle of the page, the entry under Y should be 1.

page 79:   In row 1, column 4 of Table 2.4, the second congruence should have b congruent to 18.

page 82:  In exercise 10, insert the letter P between the 39th and 40th character in the ciphertext.

page 102:  In Example 2.4.6, the 8th five-letter group in the ciphertext should be OANTN.

page 106:  In Exercise 6, the first five-letter group in the second line of ciphtertext should be AAOET.

page 108:  The first part of the third line from the bottom of the page should read L enciphers as O.

page 176:  In part (b) of Exercise 15, the first letter of the ciphertext should be Q.

page 188:  The third and second lines from the bottom of the page  should be g(000) = (1 + 0 + 0 0 + 0 0) MOD 2 = 1 and g(001) = (1 + 0 + 0 0 + 0 1) MOD 2 = 1.

page 210:  In Example 3.4.1, the key should be k = 00101011.  Then the encipherment at the bottom of the page should read
plain   10101100 10010110 00001000
key     00101011 00101011 00101011
-------------------------------------
cipher  10000111 10111101 00100011

page 219:  In the third line after the five displayed congruences, the phrase ". . .putting this into the second gives c4 = 0; finally, putting . . ." should read ". . .putting this into the second gives c5 = 0; finally, putting . . .".  Also, the subsequent displayed equation should read "b5'  <-- ( 1 b5 + 0 b4 + 0 b3 + 1 b2 + 1 b1) MOD 2.

page 203: In the sixth line from the bottom of the page, 26 = 64 should be 27 - 8 = 120.

page 228:  In the first full paragraph of the page, the phrase  "From (3.21) and (3.21)" should read "From the CBC formulas on page 227".

page 232:  Replace Exercise 2 with the following

(a)  Let fk1k2k3(x1 x2) be the function defined on page 224, and let Fk(x) be the corresponding Feistel function, whose formula is given at the bottom of page 224.  Calculate F101(1001) and verify that the formula for Fk-1(x), given by Fk-1(y1y2y3y4) = ((y3y4) + fk(y1y2)) || y1y2, applied to this value recovers the original string 1001.

(b)  Let fk(x) be the 3-bit-valued function defined by fk_1k_2(x1x2x3) = (k2 x1 MOD 2)((k1  x2 + 1) MOD 2)((k1 k2 x1 + x3 ) MOD 2), and let Fk(x) be the corresponding 6-bit-valued Feistel function, Fk(x), where k=k1k2 is a 2-bit key and x=x1x2x3x4x5x6 is a 6-bit plaintext.  Compute F11(001100).  Use the formula at the bottom of page 225 to compute F11-1 on the value obtained  and verify that it recovers the original string  001100.

page 261:  In Exercise 10, the number should be 239812014798221.

page 277:  In the line starting "so 243 = 232..." the portion reading "1 . 9 . 4 . 2 = 36 . 2 = 3 (mod 13)" should read "9 . 9 . 4 . 2 = 11 (mod 13)".

page 331:  In Example 5.1.1, the plaintext should be x = 10100010 and the key should be k = 0111111101.  In the last two lines on that page, t gets the value 00101010, and y gets the value 00111000.  As a consequence,  the first sentence of the next page should read SDES0111111101(10100010) = 0011100.

page 333:  In Exercise 7 (a), the displayed equations should read SDES1000000000(10000000) = 00000010 and SDES0100000000(10000000) = 01110110.

page 370-372:  In order to read primes in ascending order, continue each of the columns on page 370 through the 5th line of page 371, truncate the columns headed by the line 3083   3433 .... 6481 after the line 3413    3727  ......  6833, and prepend the last two lines of page 371 to the columns on page 372.  The corrected printing of the table is here in pdf format.

page 378:  In the answer for Exercise 3 of Section 2.6, replace each occurrence of 96 with 126, each occurrence of 180 with 210, and 192 with 252.

page 380:  The answer to exercise 9 in section 2.9 should be A = {{21, 25}, {12, 23}}; the answer to exercise 15(a) should be MUN UST LTP FHR.

page 381-382:  The answers for section 3.2 should be numbered according to the following table
 

number printed

16

17

18

7

8

10

12

13

15

correct number

1

2

3

5

6

8

10

11

13

With the corrected numbering, the answer to 5(k) should be -7,  the second answer in 6(f) should be 0.35, the answer to 8(a) should be 16094.4, and in 13 there should be a left parenthesis inserted to the left of the penultimate q.


Last modified 17 May 2004