hsslms 0.1.3
Leighton-Micali Hash-Based Signatures
Requires Python: >=3.6

python-hsslms
=============

This is an implementation of Leighton-Micali Hash-Based Signatures in Python according to `RFC 8554 <https://www.rfc-editor.org/rfc/rfc8554.html>`_. The one time signature keys are generated by using pseudo random generator, which saves a lot of memory to store the private keys in ram and on harddisk.

The implementation is meant as a reference and for educational purposes.

The implementation provides 4 classes:

* LM-OTS One-Time Signatures. These are one-time signatures; each private key MUST be used at most one time to sign a message.
* Leighton-Micali Signatures (LMS). This systemholds a fixed number of one-time signatures, i.e. LM-OTS.
* Hierarchical Signatures (HSS). This system uses a sequence of LMS.
* Persistent Hierarchical Signatures (PersHSS). The same as HSS except that the private key is stored in an encrypted file.

Installation
------------

.. code:: bash

   python3 -m pip install hsslms

Example Usage
-------------

LM-OTS
^^^^^^

.. code:: python

   from os import urandom
   from hsslms import LM_OTS_Priv

   # generate a one-time private key
   sk = LM_OTS_Priv(LMOTS_ALGORITHM_TYPE.LMOTS_SHA256_N32_W2, urandom(16), 0)
   # sign a message with the private key
   signature = sk.sign(b'abc')
   # compute the related public key
   vk = sk.gen_pub()
   # verify the signature, if invalid an exception will be raised
   vk.verify(b'abc', signature)

LMS
^^^

.. code:: python

   from os import urandom
   from hsslms import LMS_Priv

   # generate a private key
   sk = LMS_Priv(LMS_ALGORITHM_TYPE.LMS_SHA256_M32_H10, LMOTS_ALGORITHM_TYPE.LMOTS_SHA256_N32_W8)
   # sign a message with the private key, in total 2^10 signatures are available
   signature = sk.sign(b'abc')
   # compute the related public key
   vk = sk.gen_pub()
   # verify the signature, if invalid an exception will be raised
   vk.verify(b'abc', signature)

HSS
^^^

.. code:: python

   from os import urandom
   from hsslms import HSS_Priv

   # generate a private key
   sk = HSS_Priv([LMS_ALGORITHM_TYPE.LMS_SHA256_M32_H10]*2, LMOTS_ALGORITHM_TYPE.LMOTS_SHA256_N32_W1)
   # sign a message with the private key, in total 2^20 signatures are available
   signature = sk.sign(b'abc')
   # compute the related public key
   vk = sk.gen_pub()
   # verify the signature, if invalid an exception will be raised
   vk.verify(b'abc', signature)

Performance Measurements
------------------------

The measurements are done on a Ryzen 5600X, where multiprocessing
features are used with 6 cores.

Key Generation
^^^^^^^^^^^^^^

+----------+-----+-----+-----+-----+-------------+------+------+------+-------+
| Key-Type | Time[s]               | #Signatures | Size of Signature          |
+==========+=====+=====+=====+=====+=============+======+======+======+=======+
| w        | 1   | 2   | 4   | 8   |             | 1    | 2    | 4    | 8     |
+----------+-----+-----+-----+-----+-------------+------+------+------+-------+
| H5       | 0.1 | 0.1 | 0.1 | 0.1 | 32          | 8688 | 4464 | 2352 | 1296  |
+----------+-----+-----+-----+-----+-------------+------+------+------+-------+
| H10      | 0.3 | 0.2 | 0.2 | 0.7 | 1024        | 8848 | 4624 | 2512 | 1456  |
+----------+-----+-----+-----+-----+-------------+------+------+------+-------+
| H15      | 8.0 | 4.6 | 4.3 | 20.2| 32768       | 9008 | 4784 | 2672 | 1616  |
+----------+-----+-----+-----+-----+-------------+------+------+------+-------+
| H20      | 293 | 161 | 137 | 643 | 1048576     | 9168 | 4944 | 2832 | 1776  |
+----------+-----+-----+-----+-----+-------------+------+------+------+-------+
| H10/H10  | 0.6 | 0.5 | 0.5 | 1.4 | 1048576     | 17748| 9300 | 5076 | 2964  |
+----------+-----+-----+-----+-----+-------------+------+------+------+-------+
| H10/H15  | 8.1 | 4.6 | 4.2 | 21.1| 33554432    | 17908| 9460 | 5236 | 3124  |
+----------+-----+-----+-----+-----+-------------+------+------+------+-------+
| H15/H15  | 15.7| 10.4| 8.9 | 40.0| 1073741824  | 18068| 9620 | 5396 | 3284  |
+----------+-----+-----+-----+-----+-------------+------+------+------+-------+


Performance of Signature Generation:
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+----------+-------+-------+-------+-------+
| Key-Type | Time[s]                       |
+==========+=======+=======+=======+=======+
| w        |  1    |  2    |  4    |  8    |
+----------+-------+-------+-------+-------+
| H15      | 0.001 | 0.001 | 0.001 | 0.005 |
+----------+-------+-------+-------+-------+

Performance of Signature Verification:
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+----------+-------+-------+-------+-------+
| Key-Type | Time[s]                       |
+==========+=======+=======+=======+=======+
| w        |  1    |  2    |  4    |  8    |
+----------+-------+-------+-------+-------+
| H15      | 0.001 | 0.001 | 0.001 | 0.004 |
+----------+-------+-------+-------+-------+

License
=======

`MIT <https://opensource.org/licenses/MIT>`__