Last Updated 12 August 2010.

Errors found by the author

page 182, lines 7-8

A=[(A\oplus B) (left shift) B]+S_0
B=[(B\oplus A) (left shift) A]+S_1.

should be

A=[(A\oplus B) (left shift) B]+S_{2i}
B=[(B\oplus A) (left shift) A]+S_{2i+1}.

page 257, lines 24 and 29: 01 should be 10 (2 in binary).


Error found by Ari Salomon

page 44, line 7. "numebr" should be "number"


Error found by Stephen Fuld

In going through your book, I found an error, not in cryptography, where you are far more expert
than me, but in history. On page 162, you state that NSA caused the changes from Lucifer's 128
bits to 56, and in the S-box design. Similarly, on page 171 you state that IBM's original
proposal was for a 128 bit key. These are incorrect. The original plan for DES was for 64 bits.
There was no way, given the limitations on the number of transistors available that a 128 bit
device was remotely possible. You even quote Coppersmith's article on the limitation on the size
of the S-boxes, which would have certainly been less a size issue than trying to fit a key
length. Remember, Lucifer was a microcode (i.e software) implementation and the NBS requirement
was for a pure hardware solution. Then there is the reduction from the original planned 64 to the
56 bit key length. This was a result of IBM's internal design rules that required parity on all
internal registers with in a chip. That is why the other 8 bits are the parities of the bytes of
the 56 bits. This is all discussed in Walter Tuchman's (the manager of the IBM group that
developed DES) speech when he accepted the National Cryptography Award. This speech is reprinted
in Dorothy Dennet's book "Internet Besieged". There is also his quote made at the time that the
design was IBM's and that NSA did not change a single wire, though he acknowledged their help and
consultation. He personally picked the S boxes from a set of choices generated randomly but
according to a set of heuristics (mostly stated in Coppersmith's article) by a program running on
a 360/91, at the time the largest IBM computer ever made. I only make these points because the
"conspiracy theorists" seem to be taking over the world and this is one that can be set straight.


Error found by Jeff Wiegley

Page 167, Figure 7.12 is wrong. See the correct version here.


Error found by Craig Bauer

Page 84, Table 3.17b. The last letter on row 3 should be "i", not "t".


"Well, well, you have committed an error, that's all, Monsieur Paganel."
"What, Monsieur McNabbs! you tell me I have committed an error?"
"An inadvertence, if you like, which you can put among the ERRATA in the next edition."
Paganel, highly incensed at his geographical knowledge being brought in question, and even jested
about, allowed his ill-humor to get the better of him, and said:
"Know, sir, that my books have no need of such ERRATA."
"Indeed! Well, on this occasion they have, at any rate," retorted McNabbs, quite as obstinate as
his opponent. 
"Sir, I think you are very annoying to-day."
"And I think you are very crabbed."

-- Jules Verne, The Castaways.