S-UNIWARD is an adaptive spatial-domain steganography method for uncompressed images. It is part of the UNIWARD family of distortion functions and uses image content to guide where embedding changes should be made.
Quick Summary
- Domain:
- uncompressed images.
- Type:
- adaptive spatial-domain method.
- Tools:
- HStego >= 0.4, the Aletheia simulator, and a research implementation in StegoLab.
- Main reading:
- it reduces detectability compared with simple LSB methods, although results depend on payload and protocol.
Use in tools
S-UNIWARD is used by HStego >= 0.4 for uncompressed images. This should be read as a method implemented by those tool versions, not as a separate algorithm named “HStego”.
For detectability experiments, StegoRank also relies on the S-UNIWARD simulator included in Aletheia. A separate S-UNIWARD research implementation is available in StegoLab.
Detectability results
In the evaluated setting, the S-UNIWARD simulator is much less detectable than simple LSB replacement methods. Its relative position against HILL depends on the payload range shown in the chart.
Simulator-based results should be interpreted as method-level results. Embedding simulators are usually slightly harder to detect than real end-user tools such as HStego, because they embed close to the theoretical limit and do not include all practical constraints of a complete tool.