sp800-90b 0.0.4

SP 800-90B entropy assesment

EntropyAssessment

Cryptographic random bit generators (RBGs), also known as random number generators (RNGs), require a noise source that produces digital outputs with some level of unpredictability, expressed as min-entropy. SP 800-90B provides a standardized means of estimating the quality of a source of entropy.

Installing

Prerequisites

You will need to have the bz2 and 'divsufsort' libraries installed, as well as a g++-compatible compiler that suports c++11. On debian/ubuntu like systems the following command sould be sufficient:

sudo apt install libbz2-dev libdivsufsort-dev build-essential

You should be using a virtual environment with at least python version 3.

Using pip

You can simply run:

pip install sp800-90b

Using setuptools

Don't forget to check out the nist_impl submodule:

git submodule init
git submodule update

You will also need the setuptools and the pybind11 python package:

pip install setuptools pybind11

Now you can install the package using:

python setup.py build
python setup.py install

Manual compilation

With the same prerequisites as in the setuptools installation you can also run

make -f Manual.make

to manually compile the package.

Note: You will only be able to use it in the directory where the generated .so library is present.

Manual test

The following commands can be used for a crude test of the package:

(venv) hnj@prokrastinator:~/sp800_90b$ python
Python 3.6.9 (default, Oct  8 2020, 12:12:24) 
[GCC 8.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sp800_90b
>>> import random
>>> sp800_90b.entropy_assesment_iid(bytes(random.getrandbits(8) for i in range(1000000)))
Calculating baseline statistics...
H_original: 7.883765
H_bitstring: 0.998292
min(H_original, 8 X H_bitstring): 7.883765

** Passed chi square tests

** Passed length of longest repeated substring test

Beginning initial tests...
Beginning permutation tests... these may take some time
** Passed IID permutation tests

>>> sp800_90b.entropy_assesment_iid(bytes(random.getrandbits(7 + (i // 500000)) for i in range(1000000)))
Calculating baseline statistics...
H_original: 7.322926
H_bitstring: 0.911240
min(H_original, 8 X H_bitstring): 7.289921

igamc: UNDERFLOW
** Failed chi square tests

** Passed length of longest repeated substring test

Beginning initial tests...
Beginning permutation tests... these may take some time

Disclaimer

This software is a repackaged and slightly modified version of a NIST-developed project (that can be found here: https://github.com/usnistgov/SP800-90B_EntropyAssessment).

Original NIST Disclaimer

NIST-developed software is provided by NIST as a public service. You may use, copy and distribute copies of the software in any medium, provided that you keep intact this entire notice. You may improve, modify and create derivative works of the software or any portion of the software, and you may distribute such modifications or works. Modified works should carry a notice stating that you changed the software and should note the date and nature of any such change. Please explicitly acknowledge the National Institute of Standards and Technology as the source of the software.

Modifications

The modifications that were made were are:

• Adding the function construct_data_t in src/data_t.h with code copied from the read_file_subset function in nist_code/cpp/shared/utils.h.
• Adding the function ea_iid in src/iid_lib.cpp with code copied from the main function in nist_code/cpp/iid_main.cpp.
• Adding pybind11 boilerplate code to create a python package.

More Information

For more information on the nist code that is running, look into the original repository.

For more information on the estimation methods, see SP 800-90B.