eprintid: 79993 rev_number: 10 eprint_status: archive userid: 12243 dir: disk0/00/07/99/93 datestamp: 2026-11-13 04:11:22 lastmod: 2026-11-13 04:11:22 status_changed: 2026-11-13 04:11:22 type: thesis metadata_visibility: show contact_email: muchti.nurhidaya@uin-suka.ac.id creators_name: Hizbullah Najihan, NIM.: 22106010071 title: MODIFIKASI S-BOX PADA ALGORITMA KRIPTOGRAFI AES MENGGUNAKAN POLINOMIAL IRREDUSIBEL ALTERNATIF ATAS LAPANGAN HINGGA GF(28) ispublished: pub subjects: 560 divisions: jur_mat full_text_status: restricted keywords: AES; finite field; irreducible polynomial; S-Box; Cryptanalysis. note: M. Zaki Riyanto, S.Si., M.Sc. abstract: This research investigates the modification of the finite field structure of GF(28) in the Advanced Encryption Standard (AES) by replacing the standard irreducible polynomial with an alternative irreducible polynomial. The objectives of this research are to analyze the method for determining degree-8 irreducible polynomials over Z2, examine the algebraic structure of the finite field GF(28) constructed from the quotient rings Z2[x]/⟨m(x)⟩ and Z2[x]/⟨f(x)⟩, and analyze the effect of changing the defining irreducible polynomial on the cryptographic metrics of the S-Box. This research employs a literature study and theoretical analysis in pure algebra using a deductive approach. The results demonstrate that the alternative irreducible polynomial is irreducible over Z2 and generates the maximal ideal ⟨f(x)⟩, so that the quotient ring Z2[x]/⟨f(x)⟩ forms the finite field GF(28). Furthermore, there exists an isomorphism establishing the algebraic equivalence between the constructions of GF(28) obtained from the standard irreducible polynomial and the alternative irreducible polynomial. The resulting S-Box achieves cryptographic metrics of NL = 112, AD = 7, and DU = 4, while satisfying the Strict Avalanche Criterion (SAC), which are equivalent to those of the standard AES S-Box. Therefore, replacing the irreducible polynomial in AES does not degrade the cryptographic quality of the algorithm and provides opportunities for exploring alternative algebraic structures in modern cryptographic design. date: 2026-08-12 date_type: published pages: 143 institution: UIN SUNAN KALIJAGA YOGYAKARTA department: FAKULTAS SAINS DAN TEKNOLOGI thesis_type: skripsi thesis_name: other citation: Hizbullah Najihan, NIM.: 22106010071 (2026) MODIFIKASI S-BOX PADA ALGORITMA KRIPTOGRAFI AES MENGGUNAKAN POLINOMIAL IRREDUSIBEL ALTERNATIF ATAS LAPANGAN HINGGA GF(28). Skripsi thesis, UIN SUNAN KALIJAGA YOGYAKARTA. document_url: https://digilib.uin-suka.ac.id/id/eprint/79993/1/22106010071_BAB-I_IV-atau-V_DAFTAR-PUSTAKA.pdf document_url: https://digilib.uin-suka.ac.id/id/eprint/79993/2/22106010071_BAB-II_sampai_SEBELUM-BAB-TERAKHIR.pdf