Synthetic steganography: Methods for generating and detecting covert channels in generated media

Issues of privacy in communication are becoming increasingly important. For many people and businesses, the use of strong cryptographic protocols is sufficient to protect their communications. However, the overt use of strong cryptography may be prohibited or individual entities may be prohibited from communicating directly. In these cases, a secure alternative to the overt use of strong cryptography is required. One promising alternative is to hide the use of cryptography by transforming ciphertext into innocuous-seeming messages to be transmitted in the clear. ^ In this dissertation, we consider the problem of synthetic steganography: generating and detecting covert channels in generated media. We start by demonstrating how to generate synthetic time series data that not only mimic an authentic source of the data, but also hide data at any of several different locations in the reversible generation process. We then design a steganographic context-sensitive tiling system capable of hiding secret data in a variety of procedurally-generated multimedia objects. Next, we show how to securely hide data in the structure of a Huffman tree without affecting the length of the codes. Next, we present a method for hiding data in Sudoku puzzles, both in the solved board and the clue configuration. Finally, we present a general framework for exploiting steganographic capacity in structured interactions like online multiplayer games, network protocols, auctions, and negotiations. Recognizing that structured interactions represent a vast field of novel media for steganography, we also design and implement an open-source extensible software testbed for analyzing steganographic interactions and use it to measure the steganographic capacity of several classic games. ^ We analyze the steganographic capacity and security of each method that we present and show that existing steganalysis techniques cannot accurately detect the usage of the covert channels. We develop targeted steganalysis techniques which improve detection accuracy and then use the insights gained from those methods to improve the security of the steganographic systems. We find that secure synthetic steganography, and accurate steganalysis thereof, depends on having access to an accurate model of the cover media

A Snake Game Steganography Method based on S-Boxes

Steganography is the art and science of concealing the existence of information within seemingly innocuous carriers or it is a communication method in such a way that the presence of a message cannot be detected. There are a variety of digital carriers or places like images, audio files, text, html, etc. where data can be hidden. In this study, we proposed a game steganography method using snake game as the cover medium. We aim to hide the secret data by estimating the each move of the bait called “vitamin”. In other words, we compute coordinates of the vitamin according to the unit components of secret data. Meanwhile, we plan to complicate the game platform and establish a nonlinear relationship between the vitamin location and secret data by employing DES S-boxes. These operations render the proposed scheme more resilient against the possible steganographic attacks and make the extraction procedure more complicated. Therefore, security and imperceptibility have been kept as the focus of interest in the scope of this study. Besides, significant capacity rates have been obtained by each move. The performed experiments offer significant results to support these claims

Steganography Application Using Combination of Movements in a 2D Video Game Platform

Steganography represents the art of hiding information within a harmless medium such as digital images, video, audio, etc. Its purpose is to embed and transmit a message without raising suspicion to a third party or attacker who wishes to obtain that secret information. This research aims to propose a methodology with steganography using as a cover object a 2D platform video game. The experimentation model followed consists of using the combination of horizontal and vertical movements of the enemies by applying the numbering in base 5 or quinary where each character of the message is assigned a quinary digit. In the proposal for improvement the video game is set with 20 enemies per level along the map. The concealment is divided into 3 phases from the choice of the message, allocation of quinary values and generation of the videogame level. Finally, the limitations found will be presented based on experimentation

How Fast Can We Play Tetris Greedily With Rectangular Pieces?

Consider a variant of Tetris played on a board of width $w$ and infinite height, where the pieces are axis-aligned rectangles of arbitrary integer dimensions, the pieces can only be moved before letting them drop, and a row does not disappear once it is full. Suppose we want to follow a greedy strategy: let each rectangle fall where it will end up the lowest given the current state of the board. To do so, we want a data structure which can always suggest a greedy move. In other words, we want a data structure which maintains a set of $O(n)$ rectangles, supports queries which return where to drop the rectangle, and updates which insert a rectangle dropped at a certain position and return the height of the highest point in the updated set of rectangles. We show via a reduction to the Multiphase problem [P\u{a}tra\c{s}cu, 2010] that on a board of width $w=\Theta(n)$, if the OMv conjecture [Henzinger et al., 2015] is true, then both operations cannot be supported in time $O(n^{1/2-\epsilon})$ simultaneously. The reduction also implies polynomial bounds from the 3-SUM conjecture and the APSP conjecture. On the other hand, we show that there is a data structure supporting both operations in $O(n^{1/2}\log^{3/2}n)$ time on boards of width $n^{O(1)}$, matching the lower bound up to a $n^{o(1)}$ factor.Comment: Correction of typos and other minor correction