Message 1 contains the following plain-text and will be referred to as M1:

          Steganography is the art and science of communicating in a way which
          hides the existence of the communication. In contrast to cryptography,
          where the "enemy" is allowed to detect, intercept and modify messages
          without being able to violate certain security premises guaranteed by
          a cryptosystem, the goal of steganography is to hide messages inside
          other "harmless" messages in a way that does not allow any "enemy" to
          even detect that there is a second secret message present 
          [Markus Kuhn 1995-07-03].

Message 2 is a satellite image which will be referred to as M2:

________________________

    5     The satellite photograph is of a major Soviet strategic bomber
          base near Dolon, Kazakhstan taken August 20, 1966.  An Executive
          Order, signed by President Clinton on 23 February 1995, has
          authorized the declassification of satellite photographs
          collected by the U.S. intelligence community during the 1960's.
          This and other photographs are available on the Internet via U.S.
          Geological Survey - National Mapping Information - EROS Data
          Center.  http://edcwww.cr.usgs.gov/dclass.