DAFTAR ISI
HALAMAN JUDUL .............................................................................................. i HALAMAN PENGESAHAN PEMBIMBING ................................................... ii HALAMAN PENGESAHAN PENGUJI ........................................................... iii PERNYATAAN KEASLIAN TESIS ................................................................. iv HALAMAN PERSEMBAHAN ........................................................................... v HALAMAN MOTTO .......................................................................................... vi KATA PENGANTAR ......................................................................................... vii ABSTRAK ............................................................................................................ ix DAFTAR ISI .......................................................................................................... x DAFTAR GAMBAR .......................................................................................... xiii DAFTAR TABEL ............................................................................................... xv BAB I PENDAHULUAN ...................................................................................... 1 1.1
Latar Belakang ......................................................................................... 1
1.2
Rumusan Masalah .................................................................................... 3
1.3
Batasan Masalah ....................................................................................... 4
1.4
Tujuan ....................................................................................................... 4
1.5
Manfaat ..................................................................................................... 5
1.6
Review Penelitian ..................................................................................... 5
1.7
Metodologi Penelitian .............................................................................. 9
1.8
Sistematika Penulisan ............................................................................. 11
BAB II LANDASAN TEORI ............................................................................. 12 2.1
Citra Digital ............................................................................................ 12
2.2
File Signature ......................................................................................... 13
2.3
Hashing .................................................................................................. 14
2.4
Kriptografi .............................................................................................. 14
2.5
Algoritma Kriptografi ............................................................................. 15
2.5.1.
Algoritma Simetris .......................................................................... 15
2.5.2.
Algoritma Asimetris ........................................................................ 16
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2.6
Keamanan Algoritma Kriptografi .......................................................... 17
2.7
Rivest Shamir Adleman (RSA) ............................................................... 18
2.7.1.
Landasan Matematis Algoritma RSA ............................................. 19
2.7.1.1 Bilangan Prima ............................................................................ 19 2.7.1.2 Aritmatika Modulus .................................................................... 19 2.7.1.3 Faktor Pembagi Bersama Terbesar.............................................. 20 2.7.1.4 Invers Modulo.............................................................................. 20 2.7.1.5 Teorema Euler ............................................................................. 21 2.7.2.
Perhitungan Matematis Algoritma RSA ......................................... 21
2.8
Teori Chaos ............................................................................................ 23
2.9
Chaos dan Logistic Map ......................................................................... 24
2.10
Arnold Cat Map(ACM) .......................................................................... 27
2.11
Operasi XOR .......................................................................................... 28
2.12
Analisis Kemanan Enkripsi .................................................................... 29
2.12.1
Analisis keamanan algoritma Chaos (Cipherimage) ...................... 29
2.12.2
Analisis keamanan algoritma Chaos dan RSA (Ciphertext) ........... 33
BAB II METODOLOGI PENELITIAN ........................................................... 35 3.1
Rancangan Skema Algoritma Enkripsi Ganda ....................................... 35
3.2
Rancangan Skema Algoritma Enkripsi dan Dekripsi ............................. 37
3.2.1
Rancangan Skema Enkripsi ............................................................ 38
3.2.2
Rancangan Skema Dekripsi ............................................................ 41
3.3
Rancangan Antarmuka Pengguna .......................................................... 42
3.4
Alat dan Bahan Penelitian ...................................................................... 44
3.4.1
Perangkat Lunak (Software)............................................................ 44
3.4.2
Perangkat Keras (Hardware) .......................................................... 45
3.4.3
Bahan Penelitian.............................................................................. 45
3.5
Rancangan Analisa dan Pengujian Algoritma ........................................ 47
3.5.1
Pengujian Enkripsi Chaos ............................................................... 47
3.5.2
Pengujian Enkripsi Berbasis Chaos dan RSA (Chiphertext) .......... 54
BAB IV IMPLEMENTASI DAN ANALISIS KEMANAN............................ 56 4.1
Implementasi .......................................................................................... 56
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4.1.1
Skenario Penggunaan Aplikasi ....................................................... 56
4.1.2
Flowchart Penggunaan Enkripsi Ganda Pada Citra ........................ 58
4.1.3
Hasil Enkripsi dan Dekripsi ............................................................ 59
4.2
Analisis Kemanan................................................................................... 62
4.2.1
Analisis kemananan algoritma Chaos (Cipherimage) .................... 63
4.2.1.1 Analisis Diferensial ..................................................................... 64 4.2.1.1.1 Number of Pixels Change Rate (NPCR) ............................... 64 4.2.1.1.2 Unified Average Change Intensity (UACI) ........................... 66 4.2.1.2 Analisis Entropy .......................................................................... 69 4.2.1.3 Analisis Korelasi ......................................................................... 71 4.2.1.4 Analisis Sensitivitas Kunci .......................................................... 73 4.2.1.5 Analisis Histogram ...................................................................... 75 4.2.2
Analisis keamanan algoritma Chaos dan RSA (Ciphertext) ........... 78
4.2.2.1 Analisis Ruang Kunci .................................................................. 79 4.2.2.2 Analisis Serangan Bruteforce ...................................................... 80 BAB V KESIMPULAN DAN SARAN ............................................................. 85 5.1. 5.2.
Kesimpulan ............................................................................................. 85 Saran ....................................................................................................... 86
DAFTAR PUSTAKA LAMPIRAN
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DAFTAR GAMBAR
Gambar 1.1 Skema Enkripsi Ganda ........................................................................ 9 Gambar 1.2 Skema Pengujian Enkripsi Ganda ..................................................... 10 Gambar 2.1 Contoh File Signature ....................................................................... 14 Gambar 2.2 Model Kriptografi ............................................................................. 15 Gambar 2.3 Kriptografi Simetris........................................................................... 16 Gambar 2.4 Kriptografi Asimetris menggunakan dua kunci ................................ 17 Gambar 2.5. Grafik nilai Chaos dengan r = 4 dan x0 = 0,00172 ............................ 25 Gambar 2.6. Grafik nilai Chaos dengan r = 4 dan x0 = 0,00272 ............................ 26 Gambar 3.1 Rancangan Skema Enkripsi Ganda ................................................... 36 Gambar 3.2 Rancangan Enkripsi dan Deksirpsi ................................................... 36 Gambar 3.3 Rancangan enkripsi ........................................................................... 39 Gambar 3.4 Flowchart Rancangan enkripsi ganda ............................................... 40 Gambar 3.5 Rancangan Deksirpsi ......................................................................... 41 Gambar 3.6 Flowchart Rancangan Deksirpsi ....................................................... 42 Gambar 3.7 Rancangan antarmuka untuk enkripsi ............................................... 43 Gambar 3.8 Rancangan antarmuka untuk proses dekripsi .................................... 43 Gambar 3.9 Rancangan antarmuka MD5 Hash..................................................... 44 Gambar 3.10 Rancangan Analisa dan Pengujian Algoritma ................................. 47 Gambar 3.11 Flowchart pengujian keamanan algoritma Chaos........................... 47 Gambar 3.12 Flowchart pengujian keamanan algoritma Chaos dan RSA ........... 54 Gambar 4.1 Contoh skenario penggunaan enkripsi ganda .................................... 57 Gambar 4.2 Flowchart Enkripsi Ganda pada Citra ............................................... 58 Gambar 4.3 Flowchart Dekripsi pada Citra .......................................................... 59 Gambar 4.4 Flowchart Pengujian Keamanan Algoritma Chaos .......................... 63 Gambar 4.5 Grafik Nilai NPCR ............................................................................ 65 Gambar 4.6 Grafik Nilai UACI............................................................................. 67 Gambar 4.7 Grafik Nilai Entropy.......................................................................... 70 Gambar 4.8 Grafik Nilai Korelasi ......................................................................... 72
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Gambar 4.9 Flowchart Pengujian Keamanan Algoritma Chaos dan RSA ........... 79 Gambar 4.10 Grafik perkiraan waktu dekripsi dengan panjang kunci.................. 82
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DAFTAR TABEL
Tabel 1.1 Perbandingan dengan penelitian terdahulu ............................................. 7 Tabel 2.1. Hasil perhitungan nilai Chaos dengan perubahan pada nilai awal sebesar 0,001 ...................................................................... 26 Tabel 2.2 Aturan Operasi XOR............................................................................. 28 Tabel 3.1. Analisis diferensial............................................................................... 49 Tabel 3.2 Hasil Analisis UACI ............................................................................. 49 Tabel 3.3 Pengaruh x0 terhadap hasil dekripsi. ..................................................... 50 Tabel 3.4 Analisis Histogram................................................................................ 52 Tabel 3.5 Hasil Analisis Entropy .......................................................................... 53 Tabel 3.6 Hasil Analisis Korelasi ......................................................................... 54 Tabel 4.1 Hasil Enkripsi dan Dekripsi .................................................................. 60 Tabel 4.2 File Signature ........................................................................................ 61 Tabel 4.2 Hasil Analisis NPCR............................................................................. 64 Tabel 4.3 Analisis NPCR Berdasarkan Ukuran dan Type Citra ........................... 66 Tabel 4.4 Hasil Analisis UACI ............................................................................. 67 Tabel 4.5 Analisis UACI Berdasarkan Ukuran dan Type Citra ............................ 68 Tabel 4.6 Hasil Analisis Entropy .......................................................................... 69 Tabel 4.7 Hasil Analisis Entropy Berdasarkan Ukuran dan Type Citra ............... 70 Tabel 4.8 Analisis Korelasi ................................................................................... 71 Tabel 4.9 Analisis Korelasi Berdasarkan Ukuran dan Type Citra ........................ 73 Tabel 4.10 Pengaruh perubahan x0 terhadap hasil dekripsi................................... 74 Tabel 4.11 Analisis Histogram.............................................................................. 76 Tabel 4.12 Kesimpulan hasil analisis keamanan................................................... 83
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