Question

In the DES algorithm, the round input is 32 bits, which is expanded to 48 bits via:

• A. Scaling of the existing bits
• B. Duplication of the existing bits
• C. Addition of zeros
• D. Addition of ones

Hint:

In DES, bit duplication ensures compatibility with the key size while preserving the original structure of the data.

Answer 1

The Correct Option is B

In the DES (Data Encryption Standard) algorithm: - The expansion from 32 bits to 48 bits is achieved by duplicating some of the existing bits based on a predefined expansion table. - The expansion is necessary to match the key size (48 bits) used in the DES round.