
If started without any arguments it will show the following message:

===================================================================
ASAC --- A Strong(er) Adfgvx Cipher
===================================================================

(C)2016 Stefan Fendt (for the MysteryTwister C3 crypto challenge)

Usage:   ASAC <parameter> <parameter> ...

Available parameters:
---------------------

  -encode | -decode      This should be rather obvious. There is
                         no default with this parameter and if it
                         does not exist, the program will exit.

  -challenge=1|2|3|4     This sets the challenge. Challenge number
                         one just is the 10x10 Polybius square
                         alone. Challenge number two is the
                         Polybius square followed by a carry-free
                         addition of the output of the PRNG.

  -password1="ABCDE"     This sets the password for the Polybius
                         square. It should be twenty letters long.
                         It should only contain letters (and no
                         numbers!). If it is shorter than twenty
                         letters it will be extended by repetition.

  -password2="EFGHI"     This password is used for the PRNG. If
                         not specified and challenge 2 or above is
                         wanted, a warning will be generated and
                         the same password as that associated with
                         the initial Polybius square will be used.
                         The same rules apply as those for the
                         password1-option.

  -password3="JKLMN"     This password is used for the first
                         tabular transposition. It should be longer
                         than SQRT(2.0*NR_OF_CHARACTERS) and its
                         length should be pseudo-prime to password4
                         if double transposition is being used.
                         
  -password4="OPQRS"     This password is used for the first
                         tabular transposition. It should be longer
                         than SQRT(2.0*NR_OF_CHARACTERS) and its
                         length should be pseudo-prime to password
                         number three.

  -input="some text"     If your text contains more than one
                         word, be sure to use quotation marks...

  -file="filename"       This offers the options to enter (a lot
                         of) text from within a file.

  -prng-no-period        Without this flag the numbers generated by
                         the PRNG will repeat after 100 numbers.
                         With this flag, the PRNG will be
                         reshuffled after 100 numbers have been
                         generated.

  -verbose               Be verbose about the internal states and
                         boxes used for the various passes.
Example:
--------

ASHC -encode -challenge=1 -password1="YADA" -INPUT="SECRETMSG" 