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All Journal International Journal of Electrical and Computer Engineering IAES International Journal of Artificial Intelligence (IJ-AI) Jurnal Ilmu Komputer dan Informasi Jurnal Teknik ITS IPTEK Journal of Proceedings Series Bulletin of Electrical Engineering and Informatics JUTI: Jurnal Ilmiah Teknologi Informasi Bulletin of Electrical Engineering and Informatics Jurnal Simantec Jurnal Ilmiah Kursor Jurnal Teknologi Informasi dan Ilmu Komputer Journal of ICT Research and Applications International Journal of Advances in Intelligent Informatics Jurnal Inspiration Bulletin of Electrical Engineering and Informatics Emerging Science Journal Journal of Electronics, Electromedical Engineering, and Medical Informatics Indonesian Journal of Electrical Engineering and Computer Science Jurnal Nasional Teknik Elektro dan Teknologi Informasi Sewagati Jurnal Rekayasa elektrika
Tohari Ahmad
Departemen Informatika, Institut Teknologi Sepuluh Nopember (ITS)
Arts Humanities Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Dentistry Education Electrical & Electronics Engineering Energy Engineering Environmental Science Languange, Linguistic, Communication & Media Library & Information Science Public Health Social Sciences Other

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Pengembangan Metode Quad Smoothness Reduced Difference Expansion Untuk Steganography Pada Audio Danang Adi Nugroho; Tohari Ahmad Ahmad; Henning Titi Ciptaningtyas
Jurnal Teknik ITS Vol 6, No 2 (2017)
Publisher : Direktorat Riset dan Pengabdian Masyarakat (DRPM), ITS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (667.706 KB) | DOI: 10.12962/j23373539.v6i2.23501

Abstract

Steganography adalah salah satu bagian dari teknik penyembunyian data. Tujuan utama dari steganography adalah untuk menjaga orang lain agar tidak mengetahui informasi rahasia yang disembunyikan. Banyak penelitian yang telah dilakukan dalam bidang ini, khususnya steganography dengan media citra digital. Pada penelitian ini akan dilakukan penyembunyian data pada audio. Berkas audio yang akan digunakan adalah berkas audio dengan format WAV. Berkas audio tersebut memiliki panjang sampel 8-bit dan merupakan berkas audio mono atau single channel. Data yang disembunyikan pada audio merupakan berkas pesan tersembunyi berbentuk teks. Metode-metode yang diimplementasikan untuk penyembunyian data pada audio adalah general reduced difference expansion, quad-based general rde, block overlap general rde, dan quad smoothness general rde.Dari hasil analisa uji coba didapatkan bahwa pemilihan coveraudio berpengaruh pada nilai PSNR stegoaudio. Panjang coveraudio tidak berpengaruh pada kapasitas penyisipan pesan tersembunyi. GRDE dan Quad-RDE memiliki kapasitas penyimpanan lebih besar dari metode lainnya. Metode RDE adalah metode yang memiliki hasil PSNR yang lebih besar dari metode lainnya.
Steganografi Teks pada Aksara Sunda dengan Pendekatan Feature Coding Mohammad Rijal; Henning Titi Ciptaningtyas; Tohari Ahmad
Jurnal Teknik ITS Vol 7, No 1 (2018)
Publisher : Direktorat Riset dan Pengabdian Masyarakat (DRPM), ITS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23373539.v7i1.28975

Abstract

Kemajuan teknologi membuat arus informasi semakin meningkat. Kebutuhan akan transmisi data yang aman menjadi sangat penting. Dalam dunia sekuritas, dikenal istilah steganografi. Steganografi merupakan teknik untuk menyembunyikan informasi tanpa diketahui keberadaan informasi rahasia tersebut. Salah satu jenis steganografi adalah steganografi teks yang menggunakan teks sebagai media penyampaian. Aksara Sunda yang memiliki 13 rarangkén atau vokalisasi dapat digunakan sebagai media dalam steganografi teks. Metode yang ditawarkan pada penelitian ini menggunakan pendekatan Feature Coding pada aksara Sunda. Feature Coding mengubah bagian dari teks yang menjadi media untuk menyimpan bit informasi. Pada aksara Sunda, rarangkén digeser untuk menyimpan bit secret message yang menjadi masukan. Pilihan pergeseran pada penelitian ini terbagi menjadi shift all yang menggeser semua rarangkén dan shift group yang menggeser kelompok posisi rarangkén dalam satu huruf. Hasil uji coba metode menunjukkan bahwa steganografi teks pada aksara Sunda berhasil dilakukan dengan menggeser rarangkén melalui penggantian blok Unicode. Capacity ratio yang dihasilkan dipengaruhi oleh jumlah rarangkén yang ada. Pilihan shift all menghasilkan rata-rata capacity ratio 57,01 bit/kiloByte. Pilihan shift group menghasilkan rata-rata capacity ratio yang lebih besar yaitu 60,74 bit/kiloByte. Kenaikan sebesar 6,54% disebabkan oleh jumlah rarangkén pada pilihan shift group yang lebih besar dari pilihan shift all.
Reversible difference expansion multi-layer data hiding technique for medical images Pascal Maniriho; Leki Jovial Mahoro; Zephanie Bizimana; Ephrem Niyigaba; Tohari Ahmad
International Journal of Advances in Intelligent Informatics Vol 7, No 1 (2021): March 2021
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/ijain.v7i1.483

Abstract

Maintaining the privacy and security of confidential information in data communication has always been a major concern. It is because the advancement of information technology is likely to be followed by an increase in cybercrime, such as illegal access to sensitive data. Several techniques were proposed to overcome that issue, for example, by hiding data in digital images. Reversible data hiding is an excellent approach for concealing private data due to its ability to be applied in various fields. However, it yields a limited payload and the quality of the image holding data (Stego image), and consequently, these two factors may not be addressed simultaneously. This paper addresses this problem by introducing a new non-complexity difference expansion (DE) and block-based reversible multi-layer data hiding technique constructed by exploring DE. Sensitive data are embedded into the difference values calculated between the original pixels in each block with relatively low complexity. To improve the payload capacity, confidential data are embedded in multiple layers of grayscale medical images while preserving their quality. The experiment results prove that the proposed technique has increased the payload with an average of 369999 bits and kept the peak signal to noise ratio (PSNR) to the average of 36.506 dB using medical images' adequate security the embedded private data. This proposed method has improved the performance, especially the secret size, without reducing much the quality. Therefore, it is suitable to use for relatively big payloads.
Reversible data hiding method by extending reduced difference expansion Zainal Syahlan; Tohari Ahmad
International Journal of Advances in Intelligent Informatics Vol 5, No 2 (2019): July 2019
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/ijain.v5i2.351

Abstract

To keep hiding secret data in multimedia files, such as video, audio, and image considers essential for information security. Image, for instance, as the media aids data insertion securely. The use of insertion technique must ensure a reliable process on retaining data quality and capacity. However, a trade-off between the resulted image quality and the embedded payload capacity after the embedding process often occurs. Therefore, this research aims at extending the existing method of integrating confidential messages using the Reduced Difference Expansion (RDE), transform into a medical image by changing the base point, block size, and recalculating of difference. The results display that the proposed method enhances the quality of the stego image and capacity of the hidden message.
PENGGUNAAN KLASTER PIKSEL UNTUK MENINGKATKAN KINERJA REDUCED DIFFERENCE EXPANSION Adhi Prasetyo R; Tohari Ahmad
Jurnal Simantec Vol 4, No 3 (2015)
Publisher : Universitas Trunojoyo Madura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21107/simantec.v4i3.1380

Abstract

ABSTRAKReduced Difference expansion merupakan metode reversible data hiding dalam steganografi. Citra stego yang dihasilkan dari metode Reduced Difference Expansion dapat kembali ke dalam bentuk asli (cover) setelah proses ekstraksi. Kinerja dari metode ini masih dapat ditingkatkan, khususnya dalam hal kapasitas penyisipan data serta kualitas citra stego yang dihasilkan. Berdasarkan metode Reduced Difference Expansion, penelitian ini mengusulkan penggunaan metode baru untuk meningkatkan kinerja dari metode reduced difference expansion khususnya dalam hal kapasitas penyisipan data serta kualitas citra stego yang dihasilkan. Cara kerja dari metode yang diusulkan yaitu dengan membaca seluruh piksel terlebih dahulu, kemudian piksel-piksel tersebut akan dimasukkan ke dalam klaster sebelum dilakukan reduksi. Hasil percobaan yang dilakuakan pada 3 citra dataset berhasil berhasil meningkatkan kapasitas penyisipan data serta meningkatkan kualitas citra stego yang diukur dengan menggunakan PSNR.Kata Kunci: Kerahasiaan Data, Reduced Difference Expansion, Reversible Data Hiding, Steganography.ABSTRACTReduced Difference expansion is method of reversible data hiding in steganography. Stego image generated from Reduced Difference Expansion method can return to the original image (cover) after the extraction process. Performance of this method can still be improved, particularly in terms of capacity data insertion and stego image quality produced. Based on Reduced Difference Expansion method, this research proposes the use of a new method to improve the performance of the reduced difference expansion method, especially in terms of data embedding capacity and stego image quality produced. The workings of the proposed method is to read the entire pixels in advance, then the pixels will be incorporated into the cluster before reduction. Results of experiments on three image datasets successfully managed to increase capacity of data insertion and improve the quality stego image as measured by using PSNR.Keywords: Data Confidentiality, Reduced Difference Expansion, Reversible Data Hiding, Steganography.
SHARED SECRET-BASED KEY AND FINGERPRINT BINDING SCHEME Tohari Ahmad
Jurnal Ilmiah Kursor Vol 7 No 1 (2013)
Publisher : Universitas Trunojoyo Madura

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

SHARED SECRET-BASED KEY AND FINGERPRINT BINDING SCHEME Tohari Ahmad Department of Informatics, Sepuluh Nopember Institute of Technology Gedung Teknik Informatika Lt. 2, Kampus ITS Sukolilo Jln Raya ITS, Sukolilo, Surabaya, 60111 E-Mail:a tohari@if.its.ac.id Abstrak Salah satu permasalahan utama di dalam melakukan otentikasi pengguna dalam suatu sistem adalah keseimbangan antara akurasi dan kenyamanan. Akurasi berhubungan dengan kemampuan sistem untuk mengenali pengguna yang benar-benar diijinkan atau tidak diijinkan; sedangkan kenyamanan berhubungan dengan penerimaan pengguna terhadap keberadaan sistem. Kedua faktor tersebut merupakan faktor yang penting karena keduanya menentukan apakah sistem otentikasi tersebut dapat diaplikasikan atau tidak. Hal ini berdasarkan asumsi bahwa metode otentikasi yang sangat akurat tetapi sulit dilakukan, akan kurang dapat diterima oleh pengguna. Pada makalah ini, kami mengkombinasikan kemudahan penggunaan sidik jari dan akurasi kunci/kata sandi, sehingga pengguna dapat memanfaatkan kunci/kata sandi yang kuat tanpa harus menghafalnya, dengan menggunakan skema shared secret. Di dalam metode yang diusulkan ini, suatu kunci yang panjang dan random disebarkan ke titiktitik minutiae pada sidik jari, dan selanjutnya dibagi kepada masing-masing deskriptor, yang dalam hal ini dinyatakan dalam suatu vektor. Kunci tersebut hanya bisa direkonstruksi jika terdapat sejumlah deskriptor dan titik minutiae yang saling tumpang tindih. Percobaan yang dilakukan dengan menggunakan basis data publik (FVC2002DB2a) menunjukkan bahwa pendekatan yang diusulkan mempunyai performa yang bagus. Kata kunci: Sidik Jari, Keamanan Data, Otentikasi, Biometrik, Kerahasiaan Data. Abstract One of critical issues in authenticating users to a system is thebalance between accuracy and convenience. The former relates to thecapability of the system to recognize authorized or unauthorizedusers; while the later relates to the user acceptance to the system.Both are important factors since they determine whether such authentication system is applicable or not. This is based on the assumption that an accurate but hard to use authentication method hasless user acceptance. In this research, we combine the convenience of the fingerprint and the accuracy of the password such that the users have a strong password without having to memorize it, by using theshared secret scheme. In this proposed scheme, a long and random password is shared among the fingerprint minutiae and further, shared among its descriptors (in this case, they are represented by vectors). The password can only be reconstructed if there is a substantial number of overlapping descriptors and minutiae points. The experiment which is conducted on the public database, FVC2002DB2a, shows that the proposed approach has a good performance. Key words: fingerprint, data security, authentication, biometrics, data confidentiality
Evaluasi Kinerja Video Streaming Mpeg Dash Menggunakan Protokol Transport Multipath TCP Dany Primanita Kartikasari; Tohari Ahmad; Waskitho Wibisono
Inspiration: Jurnal Teknologi Informasi dan Komunikasi Vol 7, No 2 (2017): Jurnal Inspiration Volume 7 Issue 2
Publisher : STMIK AKBA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35585/inspir.v7i2.2443

Abstract

Tulisan ini menyampaikan hasil penelitian tentang efek penggunaan Multipath TCP sebagai protokol transport dalam menayangkan video streaming adaptif menggunakan MPEG DASH. Penelitian ini menguji efek penerapan mekanisme congestion control OLIA dengan penjadwal default pada video streaming, untuk dibandingkan dengan penayangan video streaming . Dari hasil penelitian didapatkan bahwa untuk kondisi jaringan yang stabil, TCP memberikan hasil yang lebih baik serta waktu unduh yang lebih kecil dibandingkan dengan MPTCP. Namun demikian dalam kondisi bandwidth yang berfluktuasi dan berbentuk anak tangga, MPTCP memberikan performa yang lebih baik dalam hal pengisian buffer dan dalam parameter waktu unduh.
Histogram-based multilayer reversible data hiding method for securing secret data Chaidir Chalaf Islamy; Tohari Ahmad
Bulletin of Electrical Engineering and Informatics Vol 8, No 3: September 2019
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (694.063 KB) | DOI: 10.11591/eei.v8i3.1321

Abstract

In this modern age, data can be easily transferred within networks. This condition has brought the data vulnerable; so they need protection at all times. To minimize this threat, data hiding appears as one of the potential methods to secure data. This protection is done by embedding the secret into various types of data, such as an image. In this case, histogram shifting has been proposed; however, the amount of secret and the respective stego image are still challenging. In this research, we offer a method to improve its performance by performing some steps, for example removing the shifting process and employing multilayer embedding. Here, the embedding is done directly to the peak of the histogram which has been generated by the cover. The experimental results show that this proposed method has a better quality of stego image than existing ones. So, it can be one of possible solutions to protect sensitive data.
Interactive Whiteboard and Instant Quiz for Multimedia Classroom Activity Ary Mazharuddin Shiddiqi; Royyana M. Ijtihadie; Emerson Eridiansyah Z; Baskoro Adi Pratomo; Tohari Ahmad; Waskhito Wibisono
IPTEK Journal of Proceedings Series Vol 1, No 1 (2014): International Seminar on Applied Technology, Science, and Arts (APTECS) 2013
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23546026.y2014i1.363

Abstract

Information and communication technology have become a very strategic aspect in supporting human life.  One of the aspects is in education, particularly the use of e-learning system. In the e-learning system, the use of multimedia (such as video conferencing) technology allows users to have an interactive meeting without having to see collocutor directly. In this system, each user communicates by using computer networks, either locally or through the internet. This trend has encouraged developers to create such applications online. However, most of them are paid application and less convenient to use. This research developed an interactive e-learning system with features such as online quiz, whiteboard, video conference and VoIP. In this system, a web based e-learning system with video VoIP provides learning activities by the interaction of both parties that lecturers and students. This system enables the teacher and user to have an interactive conversation and to have quizzes in the middle of a class. This method is aimed to evaluate the students understanding of the materials currently presented. Delay and jitter value of this system increases along with the increase number of users. With the 15 users, the Hypertext Transfer Protocol (HTTP) delay value reaching 32.3672 and 101.6028 ms for the jitter value. Furthermore with 15 users, the Real Time Messaging Protocol (RTMP0 delay value reached 51.8868 ms and 92.0052 ms for the jitter value.
Fuzzy MADM Approach for Rating of Process-Based Fraud Solichul Huda; Riyanarto Sarno; Tohari Ahmad
Journal of ICT Research and Applications Vol. 9 No. 2 (2015)
Publisher : LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.ict.res.appl.2015.9.2.1

Abstract

Process-Based Fraud (PBF) is fraud enabled by process deviations that occur in business processes. Several studies have proposed PBF detection methods; however, false decisions are still often made because of cases with low deviation. Low deviation is caused by ambiguity in determining fraud attribute values and low frequency of occurrence. This paper proposes a method of detecting PBF with low deviation in order to correctly detect fraudulent cases. Firstly, the fraudulence attributes are established, then a fuzzy approach is utilized to weigh the importance of the fraud attributes. Further, multi-attribute decision making (MADM) is employed to obtain a PBF rating according to attribute values and attribute importance weights. Finally, a decision is made whether the deviation is fraudulent or not, based on the PBF rating. Experimental validation showed that the accuracy and false discovery rate of the method were 0.92 and 0.33, respectively.
Co-Authors Adhi Prasetyo R Aditya Prapanca Agus Prihanto Agustin Tjahyaningtijas, Hapsari Peni Ahmad Hoirul Basori Akbar Pandu Segara Al Kanza, Kalyana Putri Alfian Ma’arif Alzamzami, Moch. Nafkhan Anggraini, Lusiana ANITA QOIRIAH Arsyad, Hammuda Ary Mazharuddin Shiddiqi Bagus J Santoso Bagus Jati Santos Baskoro Adi Pratomo Batamuliza, Jennifer Chaidir Chalaf Islamy Croix, Ntivuguruzwa Jean De La Danang Adi Nugroho Dany Primanita Kartikasari Diani, Nabila A'idah Dicky Irwanto Dino Budi Prakoso Djuned Fernando Djusdek Doni S. Pambudi, Doni S. Eka Putra, Ricky Emerson Eridiansyah Z Ephrem Niyigaba Fadhila, Farah Dhia Fikriansyah, Irsyad Hendro Eko Prabowo Hendro Eko Prabowo, Hendro Eko Henning Titi Ciptaningtyas Hudan Studiawan Imam Riadi Kantarama, Evelyne Leki Jovial Mahoro Lidya Amalia Rahmania Maurice Ntahobari Mohammad Rijal Mohammed Hatem Ali Al-Hooti Muhammad Fattahilah Rangkuty Muhammad Holil Muhammad Rizka Muhammad, Aditya Rizki Pascal Maniriho Pramudya, Rafli Raihan Prinandika, Arya Gading Purwono, Purwono Putra, I Kadek Agus Ariesta Radityo Anggoro, Radityo Ramadhan, Irsyad Fikriansyah Riyanarto Sarno Rochmawati, Naim Royyana M Ijtihadie Royyana M. Ijtihadie Royyana Muslim Ijtihadie Royyana Muslim Ijtihadie Safitri, Wardatul Amalia Santoso, Bagus Jati Santoso, Bagus Jati Solichul Huda Suartana, I Made Supeno Djanali Tegar Palyus Fiqar Tegar Palyus Fiqar Teja, Andika Rahman Uwizeye, Dieudonne Vinorian, Muhammad Ersya Wahyu Suadi Waskhito Wibisono Waskitho Wibisono Waskitho Wibisono Yohanes I. Riskajaya Yohanes I. Riskajaya YUNI YAMASARI Zainal Syahlan Zaini, Alfa Fakhrur Rizal Zephanie Bizimana