.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "api/gallery/privacy/analysis/plot_03_monero_traceability.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_api_gallery_privacy_analysis_plot_03_monero_traceability.py>`
        to download the full example code or to run this example in your browser via JupyterLite.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_api_gallery_privacy_analysis_plot_03_monero_traceability.py:


Traceability in Monero: when decoys fail (2018)
===============================================

Möser, Soska, Heilman, Lee, Heffan, Srivastava, Hogan, Hennessey, Miller,
Narayanan and Christin, and independently Kumar, Fischer, Tople and
Saxena, showed that most early Monero inputs could be traced.

- **Zero-mixin chain reaction.** A ring with no decoys reveals its
  output. Struck from every other ring, it can leave some of them with one
  member, which reveals theirs, and so on.
- **Guess-newest.** Coins are usually spent soon after they arrive, but
  decoys were drawn uniformly from all history, so the newest member was
  usually the real one.

If a ring of size :math:`n` mixes the real output with decoys of the same
age distribution, guessing the newest is right with probability about
:math:`1/n`; with uniform decoys, it approaches 1 as the chain grows.

.. GENERATED FROM PYTHON SOURCE LINES 22-27

.. code-block:: Python

    import matplotlib.pyplot as plt

    import blockchainkit as bk
    from blockchainkit.privacy.visualizers import plot_ring_positions








.. GENERATED FROM PYTHON SOURCE LINES 28-31

The chain reaction
------------------
Early Monero: rings of two, most without decoys.

.. GENERATED FROM PYTHON SOURCE LINES 31-42

.. code-block:: Python


    early = bk.privacy.simulate_rings(2_000, 900, ring_size=2, zero_mixin=0.6, seed=5)
    report = bk.privacy.trace_rings(early)
    cascade = report.deduced - report.zero_mixin
    print(f"{report.zero_mixin} zero-mixin inputs; the chain reaction traces {cascade} more")
    assert cascade > 0
    larger = bk.privacy.trace_rings(
        bk.privacy.simulate_rings(2_000, 900, ring_size=5, zero_mixin=0.6, seed=5)
    )
    print(f"with rings of five it traces {larger.deduced - larger.zero_mixin} more")





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    545 zero-mixin inputs; the chain reaction traces 118 more
    with rings of five it traces 2 more




.. GENERATED FROM PYTHON SOURCE LINES 43-45

Guess-newest, and the fix
-------------------------

.. GENERATED FROM PYTHON SOURCE LINES 45-64

.. code-block:: Python


    uniform = bk.privacy.simulate_rings(5_000, 1_000, ring_size=5, sampling="uniform", seed=7)
    recent = bk.privacy.simulate_rings(5_000, 1_000, ring_size=5, sampling="recent", seed=7)
    for name, rings in (("uniform decoys", uniform), ("age-matched decoys", recent)):
        print(f"{name}: newest is real in {bk.privacy.trace_rings(rings).newest_correct / 10:.0f}%")
    assert (
        bk.privacy.trace_rings(uniform).newest_correct
        > 2 * bk.privacy.trace_rings(recent).newest_correct
    )

    fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(11, 4))
    plot_ring_positions(uniform, ax=ax1)
    ax1.set_title("Uniform decoys: " + ax1.get_title())
    plot_ring_positions(recent, ax=ax2)
    ax2.set_title("Age-matched decoys: " + ax2.get_title())
    fig.tight_layout()

    plt.show()




.. image-sg:: /api/gallery/privacy/analysis/images/sphx_glr_plot_03_monero_traceability_001.png
   :alt: Uniform decoys: Newest member is the real one in 89% of rings, Age-matched decoys: Newest member is the real one in 21% of rings
   :srcset: /api/gallery/privacy/analysis/images/sphx_glr_plot_03_monero_traceability_001.png
   :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    uniform decoys: newest is real in 89%
    age-matched decoys: newest is real in 21%




.. GENERATED FROM PYTHON SOURCE LINES 65-72

Exercise
--------
Monero made rings of size 11 mandatory in 2018. Using
:func:`~blockchainkit.privacy.systems.traceability.simulate_rings`, how
much of a ledger with 60% zero-mixin rings of size 2 does the chain
reaction trace, and how much once the other 40% have size 11?
A worked solution is in :doc:`/exercises/privacy`.


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.120 seconds)


.. _sphx_glr_download_api_gallery_privacy_analysis_plot_03_monero_traceability.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: lite-badge

      .. image:: images/jupyterlite_badge_logo.svg
        :target: ../../../../lite/lab/index.html?path=api/gallery/privacy/analysis/plot_03_monero_traceability.ipynb
        :alt: Launch JupyterLite
        :width: 150 px

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_03_monero_traceability.ipynb <plot_03_monero_traceability.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_03_monero_traceability.py <plot_03_monero_traceability.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: plot_03_monero_traceability.zip <plot_03_monero_traceability.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_