Reversible Hash Function Generator

This project is a reversible hash function generator that allows you to create custom hash functions with various operators.

Compilation

To compile the example and test binaries in a build directory, follow these steps:

# Clone the repository, navigate to the project directory, create a build directory, navigate to the build directory
git clone --recursive https://github.com/username/repo.git && cd repo
mkdir build && cd build
# Configure the build using CMake
cmake ..
# Compile the solver
make search
# See how to run the solver
./search --help

Run tests

To run the tests, use the following commands:

mkdir -p build && cd build && cmake -CMAKE_BUILD_TYPE=Debug .. && make && make test

Command Line Interface

The search executable is the main interface to run the optimization solver. It takes options of the form --long[=<value>] or -s[=<value>]. The equal sign is mandatory, spaces between option flag and value are not supported. A file holding a set of options can be passed using @<filename>. Running the executable once produces a search.status file with the last setup, and be called backed using, e.g.: ./search @search.status.

It allows running:

• a mono-objective hill-climbing, with --algo=HC (the default),
• a mono-objective simulated annealing, with --algo=SA,
• a bi-objective evolutionary algorithm, with --algo=NSGA2.

Solution are encoded as a vector of indices toward a set of pre-determined parametrized hash function operators. The parameters domain can be set with --shift-* and --mult-* options.

One can pass an initial solution to HC and SA algorithms by using standard input, for example:

echo "0 3 1 2 3 101" | ./search --func-len=3 --init-sol=1

will initialize the first solution with 𓉘r2𐙤a2𐙤l3𐙤m31𓉝 (m31 being added automatically to complete the forward hash).

The solution encoding reads as:

┌ Fitness (here a mono-objective one)
│ ┌ func-len
│ │   ┌ Operators indices
│ │ ┌─┴─┐  ┌ Total number of operators (i.e. past-the-max index)
0 3 1 2 3 101

Beware that you are responsible for aligning --func-len and the size of the encoded solution.