rick hoselton writes:

...

Perry, I don't understand. If the least significant bits in my gif file follow all the "known statistical distributions", how can anyone know whether they are "just noise" or are an encrypted message,

Perry E. Metzger wrote:

Indeed -- how could the recipient even know to look,

Assume we have good public key steganography tools (I am not aware of such tools.) The recipient would have to scan a large pile of random pictures in the hope that some of the messages, when decoded using his private key, decoded into a correctly formatted message. Although prearrangement is needed, otherwise he would not be scanning this pile of random graphics for secret messages, he does not know whether he will receive a message or not, and no one else can know if he has received a message or not. For example: "I have plutonium and bondage pictures of nine year old girls for sale" My public key is 7uL623uvGjg8N-u7hO789HcysFhGyvcAgyh Interested parties should post replies stegoed into images posted on alt.binaries.pictures.erotica.blondes.dinosaurs.oral.fetish.waifs Please use only new dirty pictures to hide your message in -- not images I have already seen. " Then people can post replies without anyone knowing they are posting encrypted messages. -- ------------------------------------------------------------------ We have the right to defend ourselves | http://www.jim.com/jamesd/ and our property, because of the kind | of animals that we are. True law | James A. Donald derives from this right, not from the | arbitrary power of the omnipotent state.| jamesd@echeque.com