Supplementary material to the work https://eprint.iacr.org/2025/915.

transition.py:
  Calculations of quasidifferential transition matrix.
speedy.py:
  Specifications of the SPEEDY cipher.
printing.py:
  Different printing functions.

mixcolumn.ipynb

speedy_one_round.py:
  Gives the generate function to produce all one-round characteristics between the given input and output difference and calculates all quasidifferential trails.
oneroundcharextendedsearch.py:
  Given the previous outputs calculate the probability, and when the probability is zero calculate the next best characteristic.
Outputs/all.txt:   The results from speedy_one_round.py for all possibilities, giving us the 13799 one round differential characteristics.
Outputs/zeroprob.txt:
  The results from oneroundcharextendedsearch.py/calculatezeroprob() giving us the 6894 characteristics with probability zero.
Outputs/results_zero_to_newones.txt:
  The results from oneroundcharextendedsearch.py/zerochar() giving us the 1569 next-best characteristics with a nonzero probability for the zeror-probability characteristics

Outputs/nodes_list.csv:
  List of all 64 possible pairs (x,MC(x))
read_files_to_nodes_and_edges.py:
  Generate edges and nodes for graph.

graph_branch_and_bround_header.py:
  With the results from the previous step build a graph model containing all good one round characteristics.
graph_branch_and_bound.py:
  With the use of the graph model and a branch and bound algorithm find the best multiple round characteristic.

probability_calculations.ipynb:
  Calculates the probability of my 5-round characteristic

keyrecover.ipynb:
  Details on the key-recovery steps.