What is S-Box Substitution?

S-Box Substitution is a procedure that accepts the 48-bit input from the XOR operation containing the compressed key and expanded RPT and creates a 32-bit output utilizing the substitution technique.

The substitution is implemented by the eight substitution boxes (also known as the S-boxes). Each 8-S-boxes has a 6-bit input and a 4-bit output. The 48-bit input block is divided into 8 sub-blocks (each including 6 bits), and each sub-blocks is provided to an S-box.

The substitution in each box follows a pre-decided rule depends on a 4-row by 16- column table. The sequence of bits one and six of the input represent four rows and the sequence of bits two through five represent sixteen columns.

Because each S-box has its own table, we require eight tables, as display in table 1 to table 8, to represent the output of these boxes. The values of the inputs (row number and column number) and the values of the outputs are given as decimal numbers to store space. These need to be changed to binary.

S-Box 1

S-Box 2

S-Box 3

S-Box 4

S-Box 5

S-Box 6

S-Box 7

S-Box 8

Ginni

Updated on 16-Mar-2022 07:26:42

• Related Questions & Answers
• What is Polyalphabetic Substitution Cipher in Information Security?
• Black Box Testing Vs. White Box Testing- What’s the Difference?
• What is some lunch box Do’s and Dont’s for an underweight child?
• What is Grey Box Testing?
• What is Liskov Substitution principle and how to implement in C#?
• Which property is used to tell the browser what to do if the box's content is larger than the box itself?
• What is Box Model in CSS?
• What is a Grey Box Testing?
• What is the difference between a white box, black box, and gray box testing?
• What are the substitution techniques in information security?
• What is a page box in CSS?
• What is an alert box in JavaScript?
• The Substitution Operator in Perl
• Substitution Method in Data Structure
• What is Black Box Testing? (Techniques, Example, Types)