.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "api/gallery/wallets/addresses/plot_01_base58check_addresses.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_wallets_addresses_plot_01_base58check_addresses.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_wallets_addresses_plot_01_base58check_addresses.py:


Base58Check addresses (2009)
============================

Bitcoin's first release wrote an address as a version byte, the 20-byte
``HASH160`` of a public key and a 4-byte checksum, in base 58: the digits
and letters without 0, O, I and l, which are easily confused. A wallet
refuses to pay an address whose checksum fails, so a typo is caught unless
it happens to match the checksum, with probability

.. math::

   2^{-32} \approx 2.3 \times 10^{-10}.

The account names of :mod:`blockchainkit.structures` are bare SHA-256
digests, where every typo is just another valid account. Here every
single-character typo of an address is tried.

.. GENERATED FROM PYTHON SOURCE LINES 21-25

.. code-block:: Python

    import matplotlib.pyplot as plt

    import blockchainkit as bk








.. GENERATED FROM PYTHON SOURCE LINES 26-28

The address of a key
--------------------

.. GENERATED FROM PYTHON SOURCE LINES 28-37

.. code-block:: Python


    key = bk.crypto.public_key(1)
    address = bk.wallets.p2pkh_address(key)
    print("private key 1 ->", address)
    print("uncompressed   ->", bk.wallets.p2pkh_address(key, compressed=False))
    version, payload = bk.wallets.base58check_decode(address)
    print("version", version, "HASH160", payload.hex())
    assert address == "1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH"





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

 .. code-block:: none

    private key 1 -> 1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH
    uncompressed   -> 1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm
    version 0 HASH160 751e76e8199196d454941c45d1b3a323f1433bd6




.. GENERATED FROM PYTHON SOURCE LINES 38-40

Every single-character typo
---------------------------

.. GENERATED FROM PYTHON SOURCE LINES 40-63

.. code-block:: Python


    alphabet = bk.wallets.ALPHABET
    typos = [
        address[:i] + c + address[i + 1 :]
        for i in range(len(address))
        for c in alphabet
        if c != address[i]
    ]
    accepted = [t for t in typos if bk.wallets.is_valid_address(t)]
    print(f"{len(typos):,} typos, {len(accepted)} accepted")
    assert not accepted

    # An unchecked hex name accepts every typo: each is some other account.
    plain = bk.crypto.sha256(bk.crypto.encode_point(key)).hex()
    plain_typos = len(plain) * 15

    fig, ax = plt.subplots(figsize=(6, 4))
    ax.bar(["hex digest", "Base58Check"], [plain_typos, len(accepted)], color=["#dc2626", "#2563eb"])
    ax.set(ylabel="single-character typos accepted")
    ax.set_title(f"Of {len(typos):,} typos, the checksum refuses all")
    fig.tight_layout()
    plt.show()




.. image-sg:: /api/gallery/wallets/addresses/images/sphx_glr_plot_01_base58check_addresses_001.png
   :alt: Of 1,938 typos, the checksum refuses all
   :srcset: /api/gallery/wallets/addresses/images/sphx_glr_plot_01_base58check_addresses_001.png
   :class: sphx-glr-single-img


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

 .. code-block:: none

    1,938 typos, 0 accepted




.. GENERATED FROM PYTHON SOURCE LINES 64-69

Exercise
--------
How many of the typos that swap two neighbouring characters does the
checksum accept?
A worked solution is in :doc:`/exercises/wallets`.


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

   **Total running time of the script:** (0 minutes 0.054 seconds)


.. _sphx_glr_download_api_gallery_wallets_addresses_plot_01_base58check_addresses.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/wallets/addresses/plot_01_base58check_addresses.ipynb
        :alt: Launch JupyterLite
        :width: 150 px

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

      :download:`Download Jupyter notebook: plot_01_base58check_addresses.ipynb <plot_01_base58check_addresses.ipynb>`

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

      :download:`Download Python source code: plot_01_base58check_addresses.py <plot_01_base58check_addresses.py>`

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

      :download:`Download zipped: plot_01_base58check_addresses.zip <plot_01_base58check_addresses.zip>`


.. only:: html

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

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