Differential Cryptanalysis Example
This Excel Spreadsheet contains a working example of a simple Differential Cryptanalysis attack against a substitution-permutation network (SPN) with 16-bit blocks and 4-bit S-boxes.
Implemented as a Visual Basic macro for use in Excel 2007 or newer.
The Excel workbook contains two sheets. The first, "How it works", is designed for use in a lecture, in order to illustrate how Differential Cryptanalysis works. The S-box can be edited, and the illustrated algorithm steps will reflect the new S-box.
The second tab is a demonstration of an attack. You can edit the S-box, permutation, and key schedule. The macros will then perform the attack and show the most-likely value of part of key K5.
The textbook referenced in the spreadsheet is Cryptography Theory and Practice 3rd ed. by Douglas Stinson.
Interactive Illustration of the Algorithm:
Copyright (c) 2011 Braden MacDonald
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