Unlike differential cryptanalysis, which uses pairs of chosen plaintexts with a fixed XOR difference, integral cryptanalysis uses sets or even multisets of chosen plaintexts of which part is held constant and another part varies through all possibilities. For example, an attack might use 256 chosen plaintexts that have all but 8 of their bits the same, but all differ in those 8 bits. Such a set necessarily has an XOR sum of 0, and the XOR sums of the corresponding sets of ciphertexts provide information about the cipher's operation. This contrast between the differences of pairs of texts and the sums of larger sets of texts inspired the name "integral cryptanalysis", borrowing the terminology of calculus.
Kyungdeok Hwang, Wonil Lee, Sungjae Lee, Sangjin Lee, and Jongin Lim (February 2002). "Saturation Attacks on Reduced Round Skipjack" (PDF). 9th International Workshop on Fast Software Encryption (FSE '02). Leuven: Springer-Verlag. pp. 100–111. Retrieved 2007-03-03.
Lars Knudsen, David Wagner (December 11, 2001). "Integral cryptanalysis" (PDF/PostScript). 9th International Workshop on Fast Software Encryption (FSE '02). Leuven: Springer-Verlag. pp. 112–127. Retrieved 2006-11-30.