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rick hoselton writes:

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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,

If your attacker has a more sophisticated statistical model of noise distributions than you do, then he can deduce the existence of message.

Indeed -- how could the recipient even know to look, unless these things arrived regularly and with a fully standardized form of stegonography, in which case why bother, all you've done is come up with a very odd form of transfer encoding.

If the recipient does know to look, that implies either that there is a hint, in which case the stegonography is useless, or it implies that you have prearrangement, in which case my comments on prearrangement hold.

Well, there's things like the subliminal channel in DSS (discussed in Applied Cryptography) whereby a DSS chip could leak bits of a user's private key. In the channel discussed, even if the user suspected the existence of the channel, there's no way he can prove it. Now, that's steganography! -----BEGIN PGP SIGNATURE----- Version: 2.6ui iQCVAgUBMAfXAI4k1+54BopBAQHF4AQA2jRHvyKQ0ojYj7GHWpmZ+hz84dsXDtUS NJHqxjjIK1RtvPFAm4QI8p3lt/ovGKLH+CjpC0QuHZ0B3O3INkz/zD7IwsU+1SJA QycBquLvh7Q/dPkZ6J6P87Bmy0gzNBJrvW7rxLuOQyu9EOUtixFS2H9lDNa8zISp xZ/4yrb1/ZE= =NKwt -----END PGP SIGNATURE----- -- Thank you VERY much! You'll be getting a Handsome Simulfax Copy of your OWN words in the mail soon (and My Reply). <Andrew.Spring@ping.be> PGP Print: 0529 C9AF 613E 9E49 378E 54CD E232 DF96 Thank you for question, exit left to Funway.