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Increasing The Payload of Reversible Data Hiding Scheme Using Modified Pixel Value Ordering (PVO) Shofro, Puteri Awaliatush; Barmawi, Ari Moesriami
Review: Journal of Multidisciplinary in Social Sciences Vol. 1 No. 05 (2024): April 2024
Publisher : Lentera Ilmu Nusantara

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59422/rjmss.v1i05.326

Abstract

Reversible Data Hiding (RDH) is a kind of data hiding technique that allows the embedded data can be retrieved as needed and can restore the stego image exactly as the original image after the extraction of embedded data. Recently, RDH has been applied for medical record management, where any distortion of digital images is not allowed. Many new RDH techniques have been developed such as Pixel Value Ordering (PVO). This method is very popular because it has the Management of Medical Records: Facts and Figures for Surgeons advantage of reducing the number of pixels shifted, such that it can improve the stego image quality. However, the existing method has a low embedding capacity (31%). To overcome this problem, this paper proposed a modified Pixel Value Ordering where the difference value is expanded after sorting the pixel values resulting from the embedding process based on different values of 0 and 1. In this case, the difference values of -2, 0, 1, and 3 are used to embed the data, instead of only using the difference values 0 and 1. The proposed method also uses the frequency of bit 0 and 1 in the message to determine the pixels mapping that can be used to embed the message. The experiments results show that the proposed method achieved an average embedding capacity (37%) and obtained a higher PSNR value of 61 dB.
Strengthening the Authentication Mechanism of Blockchain-Based E-Voting System Using Post-Quantum Cryptography Laia, Sonitema; Barmawi, Ari Moesriami
JOIN (Jurnal Online Informatika) Vol 9 No 2 (2024)
Publisher : Department of Informatics, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/join.v9i2.1305

Abstract

Election systems often face severe challenges regarding security and trust. Threats such as vote falsification and lack of transparency in vote counting have shaken the integrity of elections in various countries. The use of blockchain technology in e-voting has been proposed as an attractive solution to overcome this problem. Several studies use blockchain for the security of electronic voting systems. The existing methods are not resistant against impersonation attacks and man-in-the-middle attacks. This research proposes a new scheme to strengthen a blockchain-based e-voting system. The blockchain used in the proposed method is Ethereum. The proposed scheme uses the modified framework and The Goldreich-Goldwasser-Halevi (GGH) signature scheme. Digital signatures generated using Goldreich-Goldwasser-Halevi (GGH) can strengthen the identity of the message sender so that enemies cannot imitate someone. In this research, the Voter's public key and anonymous ID are used by the Voter to maintain the Voter's anonymity. Based on the experimental results, it can be concluded that the proposed scheme is stronger than the previous scheme because the probability of success in impersonating the sender with the proposed scheme using an impersonation attack and man-in-the-middle attack is small.
Implementasi DSA dengan SHA-512 pada Citra Digital Menggunakan Metode Reversible Image Steganography berbasis PVO Savitri, Arildha Rahma; Adiati, Nadia Paramita Retno; Barmawi, Ari Moesriami
Info Kripto Vol 19 No 2 (2025)
Publisher : Politeknik Siber dan Sandi Negara

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56706/ik.v19i2.129

Abstract

Distribusi data digital melalui media elektronik rentan terhadap berbagai ancaman keamanan. Untuk menjamin keamanan transmisi, kriptografi digunakan sebagai mekanisme proteksi, tanda tangan digital digunakan untuk memastikan integritas dan otentikasi, sementara steganografi mencegah nilai tanda tangan dikirim secara terpisah. Penelitian ini mengimplementasikan Digital Signature Algorithm (DSA) dengan SHA-512 pada citra digital menggunakan metode reversible image steganography berbasis Pixel Value Ordering (PVO). Keunikan penelitian ini terletak pada pemanfaatan algoritma Scale Invariant Feature Transform (SIFT) untuk mengekstraksi fitur citra sebelum proses hashing, sehingga tanda tangan digital yang dihasilkan lebih tahan terhadap variasi citra. Proses meliputi pembangkitan kunci DSA, ekstraksi fitur citra, hashing dengan SHA-512, penandatanganan digital, serta penyisipan tanda tangan ke dalam citra menggunakan PVO. Hasil penelitian menunjukkan bahwa DSA dan SHA-512 dapat diimplementasikan pada citra digital baik jenis Grayscale ataupun RGB tanpa batasan ukuran pixel serta menunjukkan nilai signature yang disembunyikan tidak menyebabkan perubahan apapun terhadap cover-image. Hasil evaluasi performa dan analisis uji ketahanan metode steganografi PVO pada penelitian ini menunjukkan hasil Detection Rate, BPP, MSE, dan PSNR yang cukup baik.
Grid-based Image Encryption using Code-based Cryptography Bhagaskoro, Dian Anggoro Putro; Barmawi, Ari Moesriami
Indonesian Journal on Computing (Indo-JC) Vol. 5 No. 3 (2020): December, 2020
Publisher : School of Computing, Telkom University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34818/INDOJC.2020.5.3.493

Abstract

Recently, image is frequently sent or exchanged electronically, such that image security is important. A method for securing images is using RSA. However, RSA needs more time for securing an image. For overcoming the RSA problem, McEliece Cryptosystem is introduced to grid-based image encryption. The image is divided into blocks and each block is divided into grids, then finally McEliece Cryptosystem is applied to the pixels in the grids. Based on the experiment’s result, it was proven that the execution time of the proposed method is less than the previous one, while maintaining the security. Keywords: McEliece Cryptosystem, RSA, Image Encryption, Image Decryption, Grid 
Securing KTP Data Using QR Code Modification and Elliptic Curve Cryptography Nugraha, Rakha Aditya; Barmawi, Ari Moesriami
Indonesian Journal on Computing (Indo-JC) Vol. 9 No. 1 (2024): April, 2024
Publisher : School of Computing, Telkom University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34818/INDOJC.2024.9.1.909

Abstract

Identity Cards (KTP) are essential for Indonesian people. KTP contains personal information, such as National Identity Number (NIK), Name, Address, Gender, etc. Since KTP has essential data and is still printed conventionally, there is a vulnerability if the KTP is lost, and the owner's data is disclosed so that if an irresponsible person finds it, the data can be used for impersonating the owner. In the previous method proposed by Haque et al., [1], the data was stored in a QR Code. However, there was no verification method to legitimize the original owner, and the system did not have a login feature. To overcome the weakness of Haque et al., method [1], the owner's NIK is encrypted using the Elliptic Curve El-Gamal (ECEG) and further signed using ECDSA by the owners before storing it in the QR Code. For obtaining the owner's data in the database, the verification process should be done after the QR Code is scanned. Using the proposed method, the probability of success for a guessing attack is 1 / (n-1). Meanwhile, the probability of success for an impersonation attack is 1 / (q1 * q2 * l).
Modified Hash to Obtain Random Subset-Tree (MHORST) Using Merkle Tree and Mersenne Twister Ahmad, Faidhil Nugrah Ramadhan; Barmawi, Ari Moesriami
JOIN (Jurnal Online Informatika) Vol 10 No 2 (2025)
Publisher : Department of Informatics, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/join.v10i2.1471

Abstract

The development of quantum computing triggers new challenges in data security, particularly in addressing attacks that can solve complex mathematical problems on the fly. Several hash-based data security methods have been proposed to deal with this threat, one of them being Hash to Obtain Random Subset-Tree (HORST). However, HORST has drawbacks, such as low security, because it only uses one hash round. The security of HORST is already improved by Hash to Obtain Random Subset and Integer Composition (HORSIC). However, HORSIC’s execution time is significantly increased. The problem of this research is the low-security HORST and the high execution time of HORSIC. This research proposes a new method, Modified Hash to Obtain Random Subset-Tree (MHORST), which aims to improve the security of HORST and reduce the execution time to less than HORSI’s. MHORST uses Merkle tree, SHA-256 hashes, and Mersenne Twister to build public keys and digital signatures. Based on the experiment results, MHORST reduces the signing time by more than 3.3 times compared to HORST. MHORST reduces the verification time by more than 1.1 times HORST and 17 times HORSIC. Although the security level of MHORST decreases slightly compared to HORSIC, this method is still more secure than HORST against signature forgery.