The source code of this attempt is in https://github.com/konnnGit/mceliece-isd/tree/final.

The steps one may follow to deploy the overall application are:

1. Construct a McEliece cryptosystem based on the Galois Field parameters m and t. For this paradigm m = 7 and t = 9.

    ./McEliece.py -g -m 7 -t 9 -o 79 -v
   

   Note: The flag -o is used to define the name of the necessary binary files which contain the keys, etc. The m, t parameters are part of the file names. See manual pages A.6 for more information. Note: There is a restriction while creating keys. It is recommended not to use big values for m and t because it stalls the create process.

2. Encode a plain text message into a binary message using the public version of the Parity Check Matrix H (Hpub = HP).

    ./MatrixCodec.py -e ’Hello World’ -par 79.Hpub -v -o 79.binMsg
   

3. Encrypt the binary message into a codeword using the McEliece public key.

    ./McEliece.py -e 79.binMsg -pub 79.pub -o 79.codeword
   

   Note: One may use the included bash script

    ./create_keys_cword.sh 7 9
   

   in order to execute the steps 1,2 and 3 simultaneously. In that case, the message to be sent is included in the script. Editing it one can be change it.

4. Attack to the cipher, having three (3) options:

   a) Prange’s algorithm

    ./prange.py -c 5 -m 7 -t 9
   

   Note: In order to run the algorithms in background one may use the nohup command, like

    ./nohup prange.py -c 5 -m 7 -t 9 &
   

   b) Stern’s algorithm

    ./stern.py -c 35 -m 7 -t 9 -p 1 -l 2
   

   Note: The flag -p concerns the error bits in each k/2 coordinates. Note: The flag -c indicates how many times will be repeated the algorithm.

   c) Ball-collision-Decoding algorithm

    ./ball-coll.py -c 35 -m 7 -t 9 -p1 2 -p2 1 -q1 -1 -q2 -1 -l 2
   

   Note: In order to pass zero errors at any of -q1, -q2 coordinates, this must declared with a negative value.

5. Decrypt the cipher.

   Decrypt the cipher. In case of decrypting, the flag -d must be selected. We coose the correspoding codeword, the private key and define the output palin text name.

    ./McEliece.py -d 79.codeword -pub 79.priv -o 79.plain
   

6. Decode the decrypted binary cipher text into the initial plain text.

    ./MatrixCodec.py -d 79.plain
   

Restrictions: