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