Robust steganography is a technique of hiding secret messages in images so that the message can be recovered after additional image processing. One of the most popular processing operations is JPEG recompression. Unfortunately, most of today's steganographic methods addressing this issue only provide a probabilistic guarantee of recovering the secret and are consequently not errorless. That is unacceptable since even a single unexpected change can make the whole message unreadable if it is encrypted. We propose to create a robust set of DCT coefficients by inspecting their behavior during recompression, which requires access to the targeted JPEG compressor. This is done by dividing the DCT coefficients into 64 non-overlapping lattices because one embedding change can potentially affect many other coefficients from the same DCT block during recompression. The robustness is then combined with standard steganographic costs creating a lattice embedding scheme robust against JPEG recompression. Through experiments, we show that the size of the robust set and the scheme's security depends on the ordering of lattices during embedding. We verify the validity of the proposed method with three typical JPEG compressors and benchmark its security for various embedding payloads, three different ways of ordering the lattices, and a range of Quality Factors. Finally, this method is errorless by construction, meaning the embedded message will always be readable.

翻译：在图像中隐藏秘密信息以在图像处理额外后恢复信息的方法,是强而有力的方法。 最受欢迎的处理操作之一是 JPEG 压缩。 不幸的是, 今天解决这一问题的多数摄制方法只能提供恢复秘密的概率保障, 因而不是无误的。 这是不可接受的, 因为即使是单一意外的改变也可以使整个信息无法在图像中隐藏。 我们提议通过在再压缩过程中检查它们的行为来创建一套强大的 DCT 系数, 这需要访问目标的 JPEG 压缩器。 这样做的方法是将 DCT 系数分为64个非重叠的拉特克。 因为在再压缩过程中, 嵌入的 DCT 的多数方法只能影响同一个 DCT 块的许多其他系数。 这样, 坚固性与标准的摄取成本相结合, 创建一个对 JPEG 再压缩的强的 嵌入计划。 我们通过实验, 显示坚固的集和计划的安全性将始终取决于嵌入的拉特克( JP) 。 我们用典型的三种方法来校定安全性 。