An Optimized Key Scheduling Algorithm for CAST -128 using dynamic substitution S-box
Rekha C1, Krishnamurthy G.N2

1Rekha C, BNM institute of Technology, Dept. of Computer Science and Engg, Bangalore.
2Krishnamurthy G.N, BNM institute of Technology, Dept. of Computer Science and Engg, Bangalore, krishnamurthy.

Manuscript received on 5 August 2019. | Revised Manuscript received on 11 August 2019. | Manuscript published on 30 September 2019. | PP: 2585-2590 | Volume-8 Issue-3 September 2019 | Retrieval Number: C4920098319/2019©BEIESP | DOI: 10.35940/ijrte.C4920.098319
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Abstract: An optimized key scheduling algorithm for the 64-bit block cipher CAST-128 by using dynamically substituting of S-box. In this regard, an attempt has been made to modify key scheduling algorithm for generating subkeys of a secret-key block cipher which is CAST-128 algorithm so as to enhance performance by modifying the generation of subkeys using dynamic substitution of S-box. The CAST-128 uses four static substitution of S-box to generate subkeys, where as the proposed structure generates subkeys using substitution of S-box dynamically to provides the performance of CAST-128. The approach considers different security aspects and metrics evaluation for verification.
Keywords: CAST-128, S-Box, Key scheduling algorithm.

Scope of the Article:
Algorithm Engineering