Security information method for JPEG/exif documents generally aims to prevent security attacks by protecting documents with password and watermark. Both methods cannot be used to determine the condition of data integrity at the detection stage of the information security cycle. Message Digest is the essence of a file that has a function as a digital fingerprint to represent data integrity. This study aims to compile digital fingerprints to detect changes that occurred in JPEG / exif documents in information security. The research phase consists of five stages. The first stage, identification of the JPEG / exif document structure conducted using the Boyer-Moore string matching algorithm to find JPEG/exif segments location. The Second stage is segment content acquisition, conducted based on segment location and length obtained. The Third step, computing message digest for each segment using SHA512 hash function. Fourth stage, JPEG / exif document modification experiments to identified affected segments. The fifth stage is selecting and combining the hash value of the segment into the message digest. The obtained result shows the message digest for JPEG/exif documents composed of three hash values. The SOI segment hash value used to detect modifications for JPEG to png conversion and image editing. The APP1 hash value used to detect metadata editing. The SOF0 hash values use to detect modification for image recoloring, cropping and resizing — the combination from three hash values as JPEG/exif’s message digest.

Management of jpeg/exif file fingerprint with Brute Force string matching algorithm and Hash Function SHA256Metode pengamanan berkas gambar jpeg/exif saat ini hanya mencakup aspek pencegahan, belum pada aspek deteksi integritas data. Digital Signature Algorithm (DSA) adalah metode kriptografi yang digunakan untuk memverifikasi integritas data menggunakan hash value. SHA256 merupakan hash function yang menghasilkan 256-bit hash value yang berfungsi sebagai file fingerprint. Penelitian ini bertujuan untuk menyusun file fingerprint dari berkas jpeg/exif menggunakan SHA256 dan algoritma Brute Force string matching untuk verifikasi integritas berkas jpeg/exif. Penelitian dilakukan dalam lima tahap. Tahap pertama adalah identifikasi struktur berkas jpeg/exif. Tahap kedua adalah akuisisi konten segmen. Tahap ketiga penghitungan hash value. Tahap keempat adalah eksperimen modifikasi berkas jpeg/exif. Tahap kelima adalah pemilihan elemen dan penyusunan file fingerprint. Hasil penelitian menunjukkan sebuah jpeg/exif file fingerprint tersusun atas tiga hash value. SOI (Start of Image) segment hash value digunakan untuk mendeteksi terjadinya modifikasi berkas dalam bentuk perubahan tipe berkas dan penambahan objek pada konten gambar. Hash value segmen APP1 digunakan untuk mendeteksi modifikasi pada metadata berkas. Hash value segmen SOF0 digunakan untuk mendeteksi gambar yang dimodifikasi dengan teknik recoloring, resizing, dan cropping. The method of securing jpeg/exif image files currently has covered only the prevention aspect instead of the data integrity detection aspect. Digital Signature Algorithm is a cryptographic method used to verify the data integrity using hash value. SHA256 is a hash function that produces a 256-bit hash value functioning as a fingerprint file. This study aimed at compiling fingerprint files from jpeg/exif files using SHA256 and Brute Force string matching algorithm to verify the integrity of jpeg/exif files. The research was conducted in five steps. The first step was identifying the jpeg/exif file structure. The second step was the acquisition of the segment content. The third step was calculating the hash value. The fourth step was the jpeg/exif file modification experiment. The fifth step was the selection of elements and compilation of fingerprint files. The obtained results showed a jpeg/exif fingerprint file which was compiled in three hash values. The hash value of SOI segment was used to detect the occurrence of file modification in the form of file type changing and object addition on the image content. The hash value of APP1 segment was used to detect the metadata file modification. The hash value of SOF0 segment was used to detect the images modified by recoloring, resizing, and cropping techniques.

The jpeg/exif is file’s format for image produced by digital camera such as in the smartphones. The security method for jpeg/exif usages in digital communication currently only full-fill prevention aspect from three aspects of information security, prevention, detection and response. Digital Signature Algorithm (DSA) is a cryptographic method that provide detection aspect of information security by using hash-value as fingerprint of digital documents. The purpose of this research is to compile jpeg/exif file data fingerprint using the hash-value from DSA. The research conducted in four stages. The first stages is the identification of jpeg/exif file structure using Boyer-Moore string matching algorithm to locate the position of file’s segments. The second stage is segment’s content acquisition. The third stage the image files modification experiments to select the suitable element of jpeg/exif file data fingerprint. The fourth stage is the compilation of hash-values to form data fingerprint. The Obtained result has shown that the jpeg/exif file fingerprint comprises three hash value from the SOI segment, APP1's segment, and the SOF0 segment. The jpeg/exif file fingerprint can use for modified image detection, include six types of image modification there are image resizing, text addition, metadata modification, image resizing, image cropping and file type conversion

Security information method for jpeg / exif documents generally aims to prevent security attack by protecting documents with password and watermark. Both methods cannot used to determine the condition of data integrity at the detection stage of the information security cycle. Message Digest is the essence of a file that used to represent data integrity. This study aims to compile a message digest to detect changes that occur in jpeg / exif documents in information security. The research phase consists of five stages. The first stage, identification of the jpeg / exif document structure conducted using Boyer-Moore string matching algorithm to find jpeg/exif segments location. The Second stage is segment content acquisition, conducted based on segment location and length obtained. The Third step, computing message digest for each segment using SHA512 hash function. Fourth stage, jpeg / exif document modification experiments to identified affected segments. The Fifth stage is selecting and combining the hash value of the segment into message digest. Obtained result show message digest for jpeg / exif documents composed of two parts, the hash value of the SOI segment and the APP1 segment. The SOI segment value used to detect modifications for jpeg to png conversion and image editing. The APP1 hash value used to detect metadata editing. The SOF0 hash values use to detect modification for image recoloring, cropping and resizing.

Pengamanan berkas jpeg/exif dalam komunikasi digital umumnya bersifat untuk pencegahan, belum dapat digunakan untuk pendeteksian keutuhan data. File Fingerprint merupakan konsep sidik jari yang disusun berdasarkan konten dari dokumen digital. Penelitian ini bertujuan untuk menyusun file fingerprint dari berkas jpeg/exif yang dapat digunakan untuk mendeteksi terjadinya modifikasi pada berkas. Penyusunan file fingerprint dilakukan dalam lima tahap. Tahap pertama adalah identifikasi struktur berkas jpeg/exif menggunakan algoritma Boyer-Moore string matching untuk menentukan indeks lokasi segmen jpeg/exif. Tahap kedua adalah akuisisi konten segmen. Tahap ketiga adalah penghitungan hash value menggunakan hash function SHA512. Tahap keempat adalah pengujian modifikasi berkas jpeg/exif. Tahap kelima adalah penyusunan file fingerprint. Hasil yang diperoleh menunjukkan file fingerprint dari berkas jpeg/exif berasal dari tiga segmen, SOI, APP1 dan SOF0. Hash value dari segmen SOI digunakan untuk mendeteksi modifikasi dalam bentuk konversi tipe berkas dan penambahan objek pada gambar. Hash value dari segmen APP1 untuk mendeteksi modifikasi pada metadata. Hash value dari segmen SOF0 untuk mendeteksi modifikasi dalam bentuk resizing, recoloring dan cropping.  Berkas file fingerprint yang dihasilkan memiliki ukuran rata-rata 0,017% dari ukuran berkas gambar dari smartphone Asus Z00UD dan 0,015% dari ukuran berkas gambar dari smartphone Samsung Galaxy A5.