Scalar costa scheme for information embedding

TLDR

Information embedding, especially digital watermarking, has attracted attention for multimedia security, and while Costa’s 1983 scheme theoretically achieves capacity for Gaussian data, practical suboptimal schemes based on his idea have since been proposed. This study aims to provide a comprehensive performance analysis of the scalar Costa scheme (SCS), a suboptimal scalar embedding and reception technique. The authors analyze SCS for embedding into IID data under AWGN attacks without access to the original data, comparing information‑theoretic bounds with simulation results using state‑of‑the‑art coding, and examining reception after amplitude‑scaling attacks and the scheme’s invertibility. The analysis confirms that Costa’s original scheme is impractical, underscoring the need to evaluate suboptimal alternatives such as SCS.

Abstract

Research on information embedding, particularly information hiding techniques, has received considerable attention within the last years due to its potential application in multimedia security. Digital watermarking, which is an information hiding technique where the embedded information is robust against malicious or accidental attacks, might offer new possibilities to enforce the copyrights of multimedia data. In this paper, the specific case of information embedding into independent identically distributed (IID) data and attacks by additive white Gaussian noise (AWGN) is considered. The original data is not available to the decoder. For Gaussian data, in 1983, Costa proposed a scheme that theoretically achieves the capacity of this communication scenario. However, Costa's scheme is not practical. Thus, several research groups have proposed suboptimal practical communication schemes based on Costa's idea. The goal of this paper is to give a complete performance analysis of the scalar Costa scheme (SCS), which is a suboptimal technique using scalar embedding and reception functions. Information theoretic bounds and simulation results with state-of-the-art coding techniques are compared. Further, reception after amplitude scaling attacks and the invertibility of SCS embedding are investigated.