A Sufficient Condition for Private Information Hiding of Two Correlated Sources Under Multiple Access Attacks

Consider a multi-user private information-hiding scenario in which two information hiders separately embed correlated sources (S₁, S₂) into a common host source U (covertext). The i-th information hider embeds the secret source Si into the covertext U subject to a distortion constraint D_i (i = 1, 2). The outputs (stegotexts) are corrupted by a multiple access channel attack W_{y|X 1 X 2}. A sufficient condition (in single- letter form) under which (S₁, S₂) can be successfully embedded into U under W_{y|X 1 X 2} is established.