Digital steganography re-encoding resistance I'm curious to know if any papers exist on the ability of steganographically-altered image data to retain its integrity after it has been re-encoded into a different format (e.g., from PNG to JPEG). Is this an inherent trait in good steganography implementations, or is this an issue that needs to be treated separately?
I'm not sure what policy here is on reviving dead questions. I'll answer in case anyone else needs this question answered. I'm sorry, but I know of no papers on the subject (likely due to ignorance rather than non-existence, however).

As with most lossy methods of compression, JPEG aims to remove the image features that are not important or differentiable to the human eye. Unfortunately, those parts of the image are precisely where Steganography would occur (for example, in the least significant bits) - so if you had embedded data in an image, JPEG encoding would almost certainly destroy the stego data. Re-encoding image files is actually considered a good way of protecting against steganography. Since steganography is concerned with making the data as un-noticeable as possible (and in the process making it as indistinguishable to the human eye as possible) it is an entirely natural conclusion that steganography would be at odds with format changes (at least, lossy format changes. Lossless changes would not destroy any embedded steganography, unless they relied on some part of the format rather than the pixels themselves).