Perfectly secure steganography: hiding information in the quantum noise of a photograph

We show that the quantum nature of light can be used to hide a secret message within a photograph. Using this physical principle we achieve information-theoretic secure steganography, which had remained elusive until now. The protocol is such that the digital picture in which the secret message is embedded is perfectly undistinguishable from an ordinary photograph. This implies that, on a fundamental level, it is impossible to discriminate a private communication from an exchange of photographs.Comment: 5 pages, 3 figures + appendix : 5 pages, 6 figure

Provably Detectable Sequence Generation from AI Models via Steganographic Embedding

This disclosure describes techniques to produce machine-generated content with strong guarantees of detectability. Sequential content is generated by a generative artificial intelligence tool. The inference procedure used to sample content from the model is extended to provide cryptographic guarantees that the content can be detected to be synthetic. The sampling step that occurs during the generation of sequential output from a generative model is augmented with provably secure steganographic techniques. At each generation step where candidate tokens are evaluated for inclusion in the output of the AI tool, tokens that do not satisfy a cryptographically defined condition relative to previous tokens are rejected. The cryptographic condition is designed to satisfy the formal threshold of detectability desired. Outputs generated as a result of this process are detectable as synthetic by computation of statistics on top of the count of sequence positions where the condition holds

Universal Image Steganalytic Method

In the paper we introduce a new universal steganalytic method in JPEG file format that is detecting well-known and also newly developed steganographic methods. The steganalytic model is trained by MHF-DZ steganographic algorithm previously designed by the same authors. The calibration technique with the Feature Based Steganalysis (FBS) was employed in order to identify statistical changes caused by embedding a secret data into original image. The steganalyzer concept utilizes Support Vector Machine (SVM) classification for training a model that is later used by the same steganalyzer in order to identify between a clean (cover) and steganographic image. The aim of the paper was to analyze the variety in accuracy of detection results (ACR) while detecting testing steganographic algorithms as F5, Outguess, Model Based Steganography without deblocking, JP Hide&Seek which represent the generally used steganographic tools. The comparison of four feature vectors with different lengths FBS (22), FBS (66) FBS(274) and FBS(285) shows promising results of proposed universal steganalytic method comparing to binary methods

On the Gold Standard for Security of Universal Steganography

While symmetric-key steganography is quite well understood both in the information-theoretic and in the computational setting, many fundamental questions about its public-key counterpart resist persistent attempts to solve them. The computational model for public-key steganography was proposed by von Ahn and Hopper in EUROCRYPT 2004. At TCC 2005, Backes and Cachin gave the first universal public-key stegosystem - i.e. one that works on all channels - achieving security against replayable chosen-covertext attacks (SS-RCCA) and asked whether security against non-replayable chosen-covertext attacks (SS-CCA) is achievable. Later, Hopper (ICALP 2005) provided such a stegosystem for every efficiently sampleable channel, but did not achieve universality. He posed the question whether universality and SS-CCA-security can be achieved simultaneously. No progress on this question has been achieved since more than a decade. In our work we solve Hopper's problem in a somehow complete manner: As our main positive result we design an SS-CCA-secure stegosystem that works for every memoryless channel. On the other hand, we prove that this result is the best possible in the context of universal steganography. We provide a family of 0-memoryless channels - where the already sent documents have only marginal influence on the current distribution - and prove that no SS-CCA-secure steganography for this family exists in the standard non-look-ahead model.Comment: EUROCRYPT 2018, llncs styl

Pemanfaatan Kitosan Sebagai Adsorben Ion Logam Fe Pada Air Gambut Yang Akan Digunakan Sebagai Air Minum

Penelitian ini dilakukan dengan tujuan mengetahui dosis optimum kitosan dan cara teknis adsorpsi terbaik.   Kajian yang dilakukan pada penelitian ini meliputi isolasi kitosan dari kulit udang serta kajian tentang kondisi optimum adsorpsi.  Kitosan yang akan digunakan diisolasi dari limbah kulit udang yang dibuat melalui tiga tahap yakni tahap deproteinasi, demineralisasi dan deasetilasi. Penentuan kondisi optimum dilakukan dengan variasi dosis kitosan 0,5; 1,0; 1,5; 2 gram, serta variasi cara teknis adsorpsi terbaik yaitu dengan cara sheker, stirrer dan dengan cara didiamkan selama 60 menit. Proses adsorpsi terhadap sampel air gambut dilakukan dengan menggunakan sistem batch selama 60 menit pada suhu kamar dengan cara teknis adsorpsi terbaik dan  dosis optimum kitosan. Dosis optimum kitosan yang digunakan adalah 1,5 gram dengan jumlah ion Fe yang mampu diadsorpsi sebesar 0.669 mg/L dengan efektivitas 92,65%. Cara teknis adsorpsi terbaik yang digunakan yaitu dengan cara sheker dengan kapasitas adsorpsi sebesar 0,045 mg Fe/gram kitosan efektivitas 93,75%. Hasil aplikasi kitosan terhadap air gambut, kitosan efektif mereduksi ion logam Fe pada sampel KLP 1 dan KLP 2 hingga konsentrasi Fe sisa pada sampel air gambut adalah 0,05 mg/L dan 0,298 mg/L sehingga dikatakan layak digunakan sebagai air minum

Kajian Penyimpanan Data Pada Media Citra (Steganografi) Menggunakan Metode DCT (Discrete Cosine Transform)

Steganografi merupakan teknik menyembunyikan informasi digital dibalik informasi digital lainnya sehingga informasi digital yang sesungguhnya tidak kelihatan. Metode steganografi yang digunakan adalah DCT (Discrete Cosine Transform) untuk menyisipkan pesan rahasia. Citra yang telah disisipi pesan disebut citra stego. Pengolahan citra berupa kompresi pada citra stego untuk menguji ketahanannya.Penggunaan steganografi dengan metode DCT mempunyai keuntungan yaitu dapat menggunakan citra terkompresi JPEG. Citra yang telah dinormalisasi menjadi 256x256 piksel dipilih sebagai medium stego. Kemudian setelah disisipi pesan ditentukan nilai D (distance) yaitu perbedaan nilai koefisien dari 2 lokasi piksel yang dipilih untuk penyisipan. Setelah itu pesan rahasia kembali disisipkan pada medium stego yang tidak dinormalisasi dengan nilai D yang telah ditentukan kemudian dilakukan ekstraksi pesan dan dilakukan kompresi.Teknik steganografi dengan Metode DCT menghasilkan citra stego dalam ukuran kecil, mempunyai tingkat kesamaan yang tinggi dengan citra aslinya, selain itu pesan yang disembunyikan dalam citra stego tidak mudah terdeteksi. Nilai D paling baik yang dihasilkan pada penelitian ini adalah 21. Pada D = 21, citra stego masih belum tahan terhadap kompresi tetapi tingkat kesamaannya terhadap citra asli sangat tinggi