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3.1.5 Percobaan Manual
Pada bagian ini akan dilakukan pengujian dengan cara perhitungan manual dan menggunakan sistem untuk membandingkan kesesuaian hasil yang didapatkan dengan
menggunakan perhitungan manual dan dengan menggunakan sistem.
Tabel 3.3 Citra Asli 5x5 Piksel
R = 2 G = 5
B = 59 R = 8
G = 8 B =60
R = 83 G = 45
B = 65 R = 203
G = 137 B = 208
R = 255 G = 134
B = 210
R = 44 G = 88
B = 190 R = 66
G = 33 B = 88
R = 187 G = 240
B = 221 R = 44
G = 80 B = 85
R = 45 G = 23
B = 88
R = 180 G = 165
B = 142 R = 11
G = 0 B = 83
R = 199 G = 230
B = 212 R = 41
G = 55 B = 230
R = 21 G = 44
B = 192 R = 64
G = 77 B = 90
R = 0 G = 0
B = 100 R = 64
G = 62 B = 88
R = 55 G = 234
B = 121 R = 111
G = 115 B = 150
R = 99 G = 89
B = 78 R = 102
G = 102 B = 102
R = 88 G = 34
B = 55 R = 53
G = 58 B = 77
R = 101 G = 98
B = 100
Proses Penyisipan
Tabel 3.3 akan disisipi teks “panjaitan” dan pada sistem yang akan dibangun, akan menggunakan penanda awal dan akhir ALES, jadi yang akan disisipkan ke citra
adalah “ ALESpanjaitanALES “. Pada sistem yang akan dibangun metode penyisipan end of file dilakukan secara horizontal dan akan dimanfaatkan semua layer
citra yang ada, yaitu red, green, blue. Berikut ini hasil penyisipan teks terhadap citra.
Tabel 3.4 Stego-Image Bentuk Karakter
R = 2 G = 5
B = 59 R = 8
G = 8 B =60
R = 83 G = 45
B = 65 R = 203
G = 137 B = 208
R = 255 G = 134
B = 210
R = 44 G = 88
B = 190 R = 66
G = 33 B = 88
R = 187 G = 240
B = 221 R = 44
G = 80 B = 85
R = 45 G = 23
B = 88
R = 180 G = 165
B = 142 R = 11
G = 0 B = 83
R = 199 G = 230
B = 212 R = 41
G = 55 B = 230
R = 21 G = 44
B = 192
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Lanjutan Tabel 3.4
R = 64 G = 77
B = 90 R = 0
G = 0 B = 100
R = 64 G = 62
B = 88 R = 55
G = 234 B = 121
R = 111 G = 115
B = 150
R = 99 G = 89
B = 78 R = 102
G = 102 B = 102
R = 88 G = 34
B = 55 R = 53
G = 58 B = 77
R = 101 G = 98
B = 100 R = ‘’
G = ‘’ B = ‘A’
R = ‘L’ G = ‘E’
B = ‘S’ R = ‘’
G = ‘’ B = ‘p’
R = ‘a’ G = ‘n’
B = ‘j’ R = ‘a’
G = ‘i’ B = ‘t’
R = ‘a’ G = ‘n’
B = ‘’ R = ‘’
G = ‘A’ B = ‘L’
R = ‘E’ G =’S’
B = ‘’ R = ‘’
G = 0 B = 0
R = 0 G = 0
B = 0
Tabel 3.5 Stego-Image Bentuk ASCII Desimal
R = 2 G = 5
B = 59 R = 8
G = 8 B =60
R = 83 G = 45
B = 65 R = 203
G = 137 B = 208
R = 255 G = 134
B = 210
R = 44 G = 88
B = 190 R = 66
G = 33 B = 88
R = 187 G = 240
B = 221 R = 44
G = 80 B = 85
R = 45 G = 23
B = 88
R = 180 G = 165
B = 142 R = 11
G = 0 B = 83
R = 199 G = 230
B = 212 R = 41
G = 55 B = 230
R = 21 G = 44
B = 192 R = 64
G = 77 B = 90
R = 0 G = 0
B = 100 R = 64
G = 62 B = 88
R = 55 G = 234
B = 121 R = 111
G = 115 B = 150
R = 99 G = 89
B = 78 R = 102
G = 102 B = 102
R = 88 G = 34
B = 55 R = 53
G = 58 B = 77
R = 101 G = 98
B = 100 R = 42
G = 42 B = 65
R = 76 G = 69
B = 83 R = 42
G = 42 B = 112
R = 97 G = 110
B = 106 R = 97
G = 105 B = 116
R = 97 G = 110
B = 42 R = 42
G = 65 B = 76
R = 69 G =83
B = 42 R = 42
G = 0 B = 0
R = 0 G = 0
B = 0
Proses Enkripsi
Tabel 3.5 akan dienkripsi secara manual, dengan menggunakan pembangkitan kunci dan semua perhitungan secara manual. Berikut ini proses enkripsi :
• ambil bilangan prima secara acak p = 3821
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• ambil nilai x secara acak, dimana 1≤xp-1, x =1340 • hitung nilai y, dimana y = g
x
mod p y = 548 • ambil nilai k secara acak, dimana 1≤kp-1 k = 3562
• hitung cipher A g
k
mod p = 2976 • HITUNG cipher citra b = y
k
m mod p y
k
mod p = 548
3562
mod 3821 = 3762
Lakukan perhitungan terhadap semua piksel, jika diketahui y
k
mod p = 548
3562
mod 3821 = 3762, maka :
Citra0,0 : R = 3762 2 mod 3821 = 3703
G = 3762 5 mod 3821 = 3526 B = 3762 59 mod 3821 = 340
- Citra1,0 : R = 3762 8 mod 3821 = 3349
G = 3762 8 mod 3821 = 3349 B = 3762 60 mod 3821 = 281
- Citra2,0 : R = 3762 83 mod 3821 = 2745
G = 3762 45 mod 3821 = 1166 B = 3762 65 mod 3821 = 3807
- Citra3,0 : R = 3762 203 mod 3821 = 3307
G = 3762 137 mod 3821 = 3380 B = 3762 208 mod 3821 = 3012
- Citra4,0 : R = 3762 255 mod 3821 = 239
G = 3762 134 mod 3821 = 3557 B = 3762 210 mod 3821 = 2894
- Citra0,1 : R = 3762 44 mod 3821 = 1225
G = 3762 88 mod 3821 = 2450
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B = 3762 190 mod 3821 = 253 - Citra1,1 :
R = 3762 66 mod 3821 = 3748 G = 3762 33 mod 3821 = 1874
B = 3762 88 mod 3821 = 2450 - Citra2,1 :
R = 3762 187 mod 3821 = 430 G = 3762 240 mod 3821 = 1124
B = 3762 221 mod 3821 = 2245 - Citra3,1 :
R = 3762 44 mod 3821 = 1225 G = 3762 80 mod 3821 = 2922
B = 3762 85 mod 3821 = 2627 - Citra4,1 :
R = 3762 45 mod 3821 = 1166 G = 3762 23 mod 3821 = 2464
B = 3762 88 mod 3821 = 2450 - Citra0,2 :
R = 3762 180 mod 3821 = 843 G = 3762 165 mod 3821 = 1728
B = 3762 142 mod 3821 = 3085 - Citra1,2 :
R = 3762 11 mod 3821 = 3172 G = 3762 0 mod 3821 = 0
B = 3762 83 mod 3821 = 2745 - Citra2,2 :
R = 3762 199 mod 3821 = 3543 G = 3762 230 mod 3821 = 1714
B = 3762 212 mod 3821 = 2776 - Citra3,2 :
R = 3762 41 mod 3821 = 1402 G = 3762 55 mod 3821 = 576
B = 3762 230 mod 3821 = 1714
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- Citra4,2 : R = 3762 21 mod 3821 = 2582
G = 3762 44 mod 3821 = 1225 B = 3762 192 mod 3821 = 135
- Citra0,3 : R = 3762 64 mod 3821 = 45
G = 3762 77 mod 3821 = 3099 B = 3762 90 mod 3821 = 2332
- Citra1,3 : R = 3762 0 mod 3821 = 0
G = 3762 0 mod 3821 = 0 B = 3762 100 mod 3821 = 1742
- Citra2,3 : R = 3762 64 mod 3821 = 45
G = 3762 62 mod 3821 = 163 B = 3762 88 mod 3821 = 2450
- Citra3,3 : R = 3762 55 mod 3821 = 576
G = 3762 234 mod 3821 = 1478 B = 3762 121 mod 3821 = 503
- Citra4,3 : R = 3762 111 mod 3821 = 1093
G = 3762 115 mod 3821 = 857 B = 3762 150 mod 3821 = 2613
- Citra0,4 : R = 3762 99 mod 3821 = 1801
G = 3762 89 mod 3821 = 2391 B = 3762 78 mod 3821 = 3040
- Citra1,4 : R = 3762 102 mod 3821 = 1624
G = 3762 102 mod 3821 = 1624 B = 3762 102 mod 3821 = 1624
- Citra2,4 :
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R = 3762 88 mod 3821 = 2450 G = 3762 34 mod 3821 = 1815
B = 3762 55 mod 3821 = 576 - Citra3,4 :
R = 3762 53 mod 3821 = 694 G = 3762 58 mod 3821 = 399
B = 3762 77 mod 3821 = 3099 - Citra4,4 :
R = 3762 101 mod 3821 = 1683 G = 3762 98 mod 3821 = 1860
B = 3762 100 mod 3821 = 1742 dan seterusnya...
Hasil perhitungan diatas bisa dilihat pada tabel 3.6 berikut :
Tabel 3.6 Cipher Citra Hasil Dekripsi Citra Tabel 3.5
R = 3703 G = 3526
B = 340 R = 3349
G = 3349 B = 281
R = 2745 G = 1166
B = 3807 R = 3307
G = 3380 B = 3012
R = 239 G = 3557
B = 2894
R = 1225 G = 2450
B = 253 R = 3748
G = 1874 B = 2450
R = 430 G = 1124
B = 2245 R = 1225
G = 2922 B = 2627
R = 1166 G = 2464
B = 2450
R = 843 G = 1728
B = 3085 R = 3172
G = 0 B = 2745
R = 3543 G = 1714
B = 2776 R = 1402
G = 576 B = 1714
R = 2582 G = 1225
B = 135
R = 45 G = 3099
B = 2332 R = 0
G = 0 B = 1742
R = 45 G = 163
B = 2450 R = 576
G = 1478 B = 503
R = 1093 G = 857
B = 2613
R = 1801 G = 2391
B = 3040 R = 1624
G = 1624 B = 1624
R = 2450 G = 1815
B = 576 R = 694
G = 399 B = 3099
R = 1683 G = 1860
B = 1742
R = 1343 G = 1343
B = 3807 R = 3158
G = 3571 B = 2745
R = 1343 G = 1343
B = 1034 R = 1919
G = 1152 B = 1388
R = 1919 G = 1447
B = 798
R = 1919 G = 1152
B = 1343 R = 1343
G = 3807 B = 3158
R = 3571 G =2745
B = 1343 R = 1343
G = 0 B = 0
R = 0 G = 0
B = 0
Pada tabel 3.6 terdapat nilai yang melebihi nilai 255, sementara nilai yang dapat diterima oleh pewarnaan adalah 0-255, sehingga dibutuhkan teknik untuk mengubah
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nilai menjadi 8 bit, jadi setiap nilai akan diubah menjadi 2, karena kunci bilangan prima menggunakan 16-bit, pada proses ini akan dilakukan perubahan nilai menjadi
base 256, sehingga di dapat nilai seperti pada tabel 3.7 berikut ini :
Tabel 3.7 Citra Hasil Enkripsi Perubahan menjadi Base 256 R-G-B
119 198
84 14
13 1
21 21
25 13
13 1
185 142
223 10
4 14
235 52
196 12
13 11
239 229
78 13
11 201
146 253
4 9
164 82
146 14
7 9
174 100
197 1
4 8
201 106
67 4
11 10
142 160
146 4
9 9
75 192
13 3
6 12
100 185
12 10
217 178
216 13
6 10
122 64
178 5
2 6
22 201
135 10
4 45
27 28
12 9
206 6
45 163
146 9
64 198
247 2
5 1
69 89
53 4
3 10
9 87
224 7
9 11
88 88
88 6
6 6
146 23
64 9
7 2
182 143
27 2
1 12
147 68
206 6
7 6
63 63
223 5
5 14
86 243
185 12
13 10
63 63
10 5
5 4
127 128
108 7
4 5
127 167
30 4
5 3
127 128
63 4
4 5
63 223
86 5
14 12
243 185
63 13
10 5
63 5
Pesan yang dikirim adalah cipher-image pada tabel 3.7 dan kunci p = 3821, x = 1340, cipher a = 2976
Proses Dekripsi
Pada proses dekripsi, yang dibutuhkan adalah cipher-image, cipher a, dan kunci nilai p dan x. Pada proses ini, hal dilakukan mengecek panjang bit kunci yang digunakan,
dan menentukan berapa pertambahan sebelum di ubah menjadi base 256, dan mengembalikannya kedalam bentuk semula. Didapatkan citra berikut ini :
Tabel 3.8 Cipher-Image
R = 3703 G = 3526
B = 340 R = 3349
G = 3349 B = 281
R = 2745 G = 1166
B = 3807 R = 3307
G = 3380 B = 3012
R = 239 G = 3557
B = 2894 R = 1225
G = 2450 B = 253
R = 3748 G = 1874
B = 2450 R = 430
G = 1124 B = 2245
R = 1225 G = 2922
B = 2627 R = 1166
G = 2464 B = 2450
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Lanjutan Tabel 3.8
R = 843 G = 1728
B = 3085 R = 3172
G = 0 B = 2745
R = 3543 G = 1714
B = 2776 R = 1402
G = 576 B = 1714
R = 2582 G = 1225
B = 135 R = 45
G = 3099 B = 2332
R = 0 G = 0
B = 1742 R = 45
G = 163 B = 2450
R = 576 G = 1478
B = 503 R = 1093
G = 857 B = 2613
R = 1801 G = 2391
B = 3040 R = 1624
G = 1624 B = 1624
R = 2450 G = 1815
B = 576 R = 694
G = 399 B = 3099
R = 1683 G = 1860
B = 1742
R = 1343 G = 1343
B = 3807 R = 3158
G = 3571 B = 2745
R = 1343 G = 1343
B = 1034 R = 1919
G = 1152 B = 1388
R = 1919 G = 1447
B = 798 R = 1919
G = 1152 B = 1343
R = 1343 G = 3807
B = 3158 R = 3571
G =2745 B = 1343
R = 1343 G = 0
B = 0 R = 0
G = 0 B = 0
Proses perhitungan untuk dekripsi : • kunci dekripsi p = 3821, x = 1340, dan cipher a = 2976
• hitung nilai 1a
x
= a
x -1
= a
p-1-x
mod p = 2976
3821-1-1340
mod 3821 = 1360 • hitung m = ba
x
mod p sebanyak cipher citra • Sehingga didapat plain citra
- Citra0,0 : R = 3703 1360 mod 3821 = 2
G = 3526 1360 mod 3821 = 5 B = 340 1360 mod 3821 = 59
- Citra1,0 : R = 3349 1360 mod 3821 = 8
G = 3349 1360 mod 3821 = 8 B = 281 1360 mod 3821 = 60
- Citra2,0 : R = 2745 1360 mod 3821 = 83
G = 1166 1360 mod 3821 = 45 B = 3807 1360 mod 3821 = 65
- Citra3,0 : R = 3307 1360 mod 3821 = 203
G = 3380 1360 mod 3821 = 137
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B = 3012 1360 mod 3821 = 208 - Citra4,0 :
R = 239 1360 mod 3821 = 255 G = 3557 1360 mod 3821 = 134
B = 2894 1360 mod 3821 = 210 - Citra0,1 :
R = 1225 1360 mod 3821 = 44 G = 2450 1360 mod 3821 = 88
B = 253 1360 mod 3821 = 190 - Citra1,1 :
R = 3748 1360 mod 3821 = 66 G = 1874 1360 mod 3821 = 33
B = 2450 1360 mod 3821 = 88 - Citra2,1 :
R = 430 1360 mod 3821 = 187 G = 1124 1360 mod 3821 = 240
B = 2245 1360 mod 3821 = 221 - Citra3,1 :
R = 1225 1360 mod 3821 = 44 G = 2922 1360 mod 3821 = 80
B = 2627 1360 mod 3821 = 85 - Citra4,1 :
R = 1166 1360 mod 3821 = 45 G = 2464 1360 mod 3821 = 23
B = 2450 1360 mod 3821 = 88 - Citra0,2 :
R = 843 1360 mod 3821 = 180 G = 1728 1360 mod 3821 = 165
B = 3085 1360 mod 3821 = 142 - Citra1,2 :
R = 3172 1360 mod 3821 = 11 G = 0 1360 mod 3821 = 0
B = 2745 1360 mod 3821 = 83
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- Citra2,2 : R = 3543 1360 mod 3821 = 199
G = 1714 1360 mod 3821 = 230 B = 2776 1360 mod 3821 = 212
- Citra3,2 : R = 1402 1360 mod 3821 = 41
G = 576 1360 mod 3821 = 55 B = 1714 1360 mod 3821 = 230
- Citra4,2 : R = 2582 1360 mod 3821 = 21
G = 1225 1360 mod 3821 = 44 B = 135 1360 mod 3821 = 192
- Citra0,3 : R = 45 1360 mod 3821 = 64
G = 3099 1360 mod 3821 = 77 B = 2332 1360 mod 3821 = 90
- Citra1,3 : R = 0 1360 mod 3821 = 0
G = 0 1360 mod 3821 = 0 B = 1742 1360 mod 3821 = 100
- Citra2,3 : R = 45 1360 mod 3821 = 64
G = 163 1360 mod 3821 = 62 B = 2450 1360 mod 3821 = 88
- Citra3,3 : R = 576 1360 mod 3821 = 55
G = 1478 1360 mod 3821 = 234 B = 503 1360 mod 3821 = 121
- Citra4,3 : R = 1093 1360 mod 3821 = 111
G = 857 1360 mod 3821 = 115 B = 2613 1360 mod 3821 = 150
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- Citra0,4 : R = 1801 1360 mod 3821 = 99
G = 2391 1360 mod 3821 = 89 B = 3040 1360 mod 3821 = 78
- Citra1,4 : R = 1624 1360 mod 3821 = 102
G = 1624 1360 mod 3821 = 102 B = 1624 1360 mod 3821 = 102
- Citra2,4 : R = 2450 1360 mod 3821 = 88
G = 1815 1360 mod 3821 = 34 B = 576 1360 mod 3821 = 55
- Citra3,4 : R = 694 1360 mod 3821 = 53
G = 399 1360 mod 3821 = 58 B = 3099 1360 mod 3821 = 77
- Citra4,4 : R = 1683 1360 mod 3821 = 101
G = 1860 1360 mod 3821 = 98 B = 1742 1360 mod 3821 = 100
dan seterusnya... Hasil perhitungan dekripsi diatas di buat menjadi satu tabel citra hasil dekripsi, seperti
pada tabel 3.9 berikut :
Tabel 3.9 Hasil Dekripsi
R = 2 G = 5
B = 59 R = 8
G = 8 B =60
R = 83 G = 45
B = 65 R = 203
G = 137 B = 208
R = 255 G = 134
B = 210
R = 44 G = 88
B = 190 R = 66
G = 33 B = 88
R = 187 G = 240
B = 221 R = 44
G = 80 B = 85
R = 45 G = 23
B = 88
R = 180 G = 165
B = 142 R = 11
G = 0 B = 83
R = 199 G = 230
B = 212 R = 41
G = 55 B = 230
R = 21 G = 44
B = 192 R = 64
G = 77 B = 90
R = 0 G = 0
B = 100 R = 64
G = 62 B = 88
R = 55 G = 234
B = 121 R = 111
G = 115 B = 150
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Lanjutan Tabel 3.9
R = 99 G = 89
B = 78 R = 102
G = 102 B = 102
R = 88 G = 34
B = 55 R = 53
G = 58 B = 77
R = 101 G = 98
B = 100 R = 42
G = 42 B = 65
R = 76 G = 69
B = 83 R = 42
G = 42 B = 112
R = 97 G = 110
B = 106 R = 97
G = 105 B = 116
R = 97 G = 110
B = 42 R = 42
G = 65 B = 76
R = 69 G =83
B = 42 R = 42
G = 0 B = 0
R = 0 G = 0
B = 0
Ekstraksi citra dilakukan setelah proses dekripsi, dan yang pertama sekali dilakukan adalah memeriksa penanda awal, dan setelah penanda awal ditemukan langsung
dilakukan pencatatan sampai penanda akhir ditemukan kembali. Berikut tabel 3.10 hasil ekstraksi :
Tabel 3.10 Hasil Ekstraksi
R = 2 G = 5
B = 59 R = 8
G = 8 B =60
R = 83 G = 45
B = 65 R = 203
G = 137 B = 208
R = 255 G = 134
B = 210
R = 44 G = 88
B = 190 R = 66
G = 33 B = 88
R = 187 G = 240
B = 221 R = 44
G = 80 B = 85
R = 45 G = 23
B = 88
R = 180 G = 165
B = 142 R = 11
G = 0 B = 83
R = 199 G = 230
B = 212 R = 41
G = 55 B = 230
R = 21 G = 44
B = 192 R = 64
G = 77 B = 90
R = 0 G = 0
B = 100 R = 64
G = 62 B = 88
R = 55 G = 234
B = 121 R = 111
G = 115 B = 150
R = 99 G = 89
B = 78 R = 102
G = 102 B = 102
R = 88 G = 34
B = 55 R = 53
G = 58 B = 77
R = 101 G = 98
B = 100 Teks asli yang ditemukan pada citra adalah teks “panjaitan”.
3.2 Perancangan
Dalam pembuatan sebuah sistem, sebelum ketahap pemrograman dan setelah tahap analisis permasalahan harus mempunyai rancangan interface, sehingga dalam
pembuatan aplikasi semakin mudah untuk desain interface aplikasi yang akan dibangun.
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