stegsnow - whitespace steganography program

       This application was written by Matthew Kwan, who can be reached at mkwan@darkside.com.au

stegsnow  is  a  program for concealing messages in text files by appending tabs and spaces on the end of
       lines, and for extracting messages from files containing hidden messages.  Tabs and spaces are  invisible
       to most text viewers, hence the steganographic nature of this encoding scheme.

       The  data is concealed in the text file by appending sequences of up to 7 spaces, interspersed with tabs.
       This usually allows 3 bits  to  be  stored  every  8  columns.  An  alternative  encoding  scheme,  using
       alternating  spaces  and  tabs to represent zeroes and ones, was rejected because, although it used fewer
       bytes, it required more columns per bit (4.5 vs 2.67).

       The start of the data is indicated by an appended tab character, which allows the insertion of  mail  and
       news headers without corrupting the data.

       stegsnow  provides  rudimentary compression, using Huffman tables optimised for English text. However, if
       the data is not text, or if there is a  lot  of  data,  the  use  of  the  built-in  compression  is  not
       recommended, since an external compression program such as compress or gzip will do a much better job.

       Encryption  is  also  provided,  using  the ICE encryption algorithm in 1-bit cipher-feedback (CFB) mode.
       Because of ICE's arbitrary key size, passwords of any length up to 1170 characters are  supported  (since
       only 7 bits of each character are used, keys up to 1024-bytes are supported).

       If  a  message string or message file are specified on the command-line, stegsnow will attempt to conceal
       the message in the file infile if specified, or standard input otherwise.  The  resulting  file  will  be
       written to outfile if specified, or standard output if not.

       If  no message string is provided, stegsnow attempts to extract a message from the input file. The result
       is written to the output file or standard output.

       The following command will conceal the message "I am lying" in the file  infile,  with  compression,  and
       encrypted with the password "hello world". The resulting text will be stored in outfile.

              stegsnow-C-m"Iamlying"-p"helloworld"infileoutfile

       To extract the message, the command would be

              stegsnow-C-p"helloworld"outfile

       Note that the resulting message will not be terminated by a newline.

       To  prevent line wrap if text with concealed whitespace is likely to be indented by mail or news readers,
       a line length of 72 or less can be used.

              stegsnow-C-l72-m"Iamlying"infileoutfile

       The approximate storage capacity of a file can be determined with the -S option.

              stegsnow-S-l72infile

       stegsnow - whitespace steganography program

-C     Compress the data if concealing, or uncompress it if extracting.

       -fmessage-file
              The contents of this file will be concealed in the input text file.

       -lline-len
              When appending whitespace, stegsnow will always produce lines shorter than this value. By  default
              it is set to 80.

       -mmessage-string
              The contents of this string will be concealed in the input text file.  Note that, unless a newline
              is somehow included in the string, a newline will not be printed when the message is extracted.

       -ppassword
              If  this  is  set,  the data will be encrypted with this password during concealment, or decrypted
              during extraction.

       -Q     Quiet mode. If not set, the program reports statistics such as compression percentages and  amount
              of available storage space used.

       -S     Report  on  the  approximate  amount  of space available for hidden message in the text file. Line
              length is taken into account, but other options are ignored.

       -V,--version
              Display usage information and exit.

       -h,--help
              Display usage information and exit.

ice_key_create(3)

Version 1.1                                        28 Dec 1996                                       STEGSNOW(1)

stegsnow [ -CQS ] [ -h | --help ] [ -V | --version ] [ -ppasswd ] [ -lline-len ] [ -ffile | -mmessage
       ] [ infile [ outfile ]]