Detector-Informed Batch Steganography and Pooled Steganalysis

We study the problem of batch steganography when the senders use feedback from a steganography detector. This brings an additional level of complexity to the table due to the highly non-linear and non-Gaussian response of modern steganalysis detectors as well as the necessity to study the impact of the inevitable mismatch between senders' and Warden's detectors. Two payload spreaders are considered based on the oracle generating possible cover images. Three different pooling strategies are devised and studied for a more comprehensive assessment of security. Substantial security gains are observed with respect to previous art - the detector-agnostic image-merging sender. Close attention is paid to the impact of the information available to the Warden on security.