Parameter curves for Concrete
=============

This Github repository contains the code needed to generate the Parameter curves used inside Zama. The repository contains the following files:

- cpp/, Python scripts to generate a cpp file containing the parameter curves
- data/, a folder containing the data generated for previous curves. 
- estimator/, Zama's internal version of the LWE Estimator
- figs/, a folder containing various figures related to the parameter curves
- scripts.py, a copy of all scripts required to generate the parameter curves
- a variety of other python files, used for estimating the security of previous Concrete parameter sets

.. image:: logo.svg
   :align: center
   :width: 200


Example
-------------------
This is an example of how to generate the parameter curves, and save them to file.

::

    sage: load("scripts.py")
    sage: results = get_zama_curves()
    sage: save(results, "v0.sobj")
::

We can load results files, and find the interpolants.

::

    sage: load("scripts.py")
    sage: interps = []
    sage: results = load("v0.sobj")
    sage: for result in results:
    sage:     interps.append(interpolate_result(result, log_q = 64))
    sage: interps
    [(-0.040476778656126484, 1.143346508563902),
     (-0.03417207792207793, 1.4805194805194737),
     (-0.029681716023268107, 1.752723426758335),
     (-0.0263748887657055, 2.0121439233304894),
     (-0.023730136557783763, 2.1537066948924095),
     (-0.021604493958972515, 2.2696862472846204),
     (-0.019897520946588438, 2.4423829771964796),
     (-0.018504919354426233, 2.6634073426215745),
     (-0.017254242957361113, 2.7353702447139026),
     (-0.016178309410530816, 2.8493969373734758),
     (-0.01541034709414119, 3.1982749283836283),
     (-0.014327640360322604, 2.899270827311096)]
::

Finding the value of n_{alpha} is done manually. We can also verify the interpolants which are generated at the same time:

::

    # verify the interpolant used for lambda = 256 (which is interps[-1])
    sage: z = verify_interpolants(interps[-1], (128,2048), 64)
    [... code runs, can take ~10 mins ...]
    # find the index corresponding to n_alpha, which is where security drops below the target security level (256 here)
    sage: n_alpha = find_nalpha(z, 256)
    653
    
    # so the model in this case is 
    (-0.014327640360322604, 2.899270827311096, 653)
    # which corresponds to
    # sd(n) = max(-0.014327640360322604 * n +  2.899270827311096, -logq + 2), n >= 653
::

Version History
-------------------

Data for the curves are kept in /data. The following files are present:

::

    v0: generated using the {usvp, dual, decoding} attacks
    v0.1: generated using the {mitm, usvp, dual, decoding} attacks
::

TODO List
-------------------

There are several updates which are still required.
    1. Consider Hybrid attacks (WIP, Michael + Ben are coding up hybrid-dual/hybrid-decoding estimates)
    2. CI/CD stuff for new pushes to the external LWE Estimator.
    3. Fully automate the process of finding n_{alpha} for each curve.
    4. Functionality for q =! 64? This is covered by the curve, but we currently don't account for it in the models, and it needs to be done manually.
    5. cpp file generation