Asemica

This is a re-implementation of asemica which is a cipher that uses a document as a key. The original is written in Perl but this one uses the Factor programming anguage.

Usage

To use this program you need to first have Factor installed on your system. Clone the repository and change into the directory. Then you can run it by invoking the factor-vm with asemica.factor and all the necessary arguments for example on Arch Linux.

$ echo "Attack at Dawn" | factor-vm asemica.factor -m enc -c metamorphosis.txt -o enc.txt

$ cat enc.txt
they must request a little way he didn't know just getting weaker
and fur He began their skirts she fled onto her breast His bed
perhaps expected said nothing unusual was something of luxury For the
bedding was something of rain could think it had at all to sleeping a
COPYRIGHTED

$ factor-vm asemica.factor -m dec -c https://www.gutenberg.org/cache/epub/5200/pg5200.txt -i enc.txt
Attack at Dawn

The above encodes the message from stdin "Attack at Dawn" and writes the result to enc.txt. A file can be passed for the input and output using -i and -o. Additionally the key file (-c argument) may be a URL to an online file.

Practical Information

The program takes some time to start-up due to the loading of the various libraries being used so it may be beneficial to generate a custom image containing all the loaded libraries and passing it as an argument. To do this run the following commands

$ factor-vm -run=readline-listener

IN: scratchpad USE: vocabs.loader
IN: scratchpad "/path/to/repo/" add-vocab-root
IN: scratchpad USE: asemica-factor
IN: scratchpad "/some/path/cust.img" save-image-and-exit

Afterwards make sure to add -i=/some/path/cust.img to calls to the factor vm. Alternatively you can add a shebang line to the top of asemica.factor so you can run the program as a script. Running without any arguments prints out the usage.

asemica - a markov chain based cipher

usage: asemica -m mode -c <file/url> [-i <file>] [-o <file>]

Options:
  -m  either 'enc' or 'dec' for encode or decode mode
  -c  specify the corpus file or url
  -i  specify the input file (defaults to STDIN)
  -o  specify the output file (defaults to STDOUT)