 # The Block Cipher Companion

This is a book about block ciphers, written by Lars R. Knudsen and Matt Robshaw.
The book is published by Springer, and available elsewhere also e.g., from Amazon and Tesco.

Errata in the 1st edition:

• Page 58, 4th last line, "over found encryption rounds" -> "over four encryption rounds".
(thank you Steven Alexander)

• Page 86, 3rd bullet, "If should be hard ..." -> "It should be hard ..."
(thank you Steven Alexander)

• Page 158, the difference after two rounds should be 00*0 0000 00*0 00*0
(thank you Rusydi H. Makarim)

• Page 159, 5th last line, the -1 should not be in the superscript
(thank you Martin Mehl Lauridsen)

• Page 235, ref 195, "D.W. Davies and S. Murph" -> "D.W. Davies and S. Murphy"

• The below observations are from Thorsten Kranz, thank you

• p97, l2: replace the first subscript "(r,i)" by "(r,i-1)"
• p97, l15, l16: replace subscripts "(j,s-1)" by "(j,t-1)"
• p101, l-4: replace subscript "(r,i)" by "(r,i-1)"
• p105, l-6: swap the subscript of the keys: correct is "k_2=i and k_1=j"
• p128, l6: the equations are erroneous
• p137, Fig.74, 2.f: replace "a_i" by "u_i"
• p163, l-3,l-2: replace "encryption" by "decryption"
• p166, l8: replace "Dom(h)" by "Dom(f)"
• p171, l21: replace subscript "1" by "1,t"
• p190, l9: replace subscript "n+m-2" by "m-2" and replace superscript "2n-2" by "n+m-2"

• p128, l6: the correct equations are
k0 = m0 + c0 + c1 + c2 + c3
k1 = m1 + c1 + c2 + c3
k2 = m2 + c0 + c1 + c3
k3 = m3 + c0 + c3