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A small and insanely fast ARCFOUR (RC4) cipher implementation of Python

Project description

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A small and insanely fast ARCFOUR (RC4) cipher implementation of Python.

  • Strongly focused on performance; entire source code is written in C.
  • Easily installable; single file with no dependency.


Below is benchmark metrics against 3 major RC4 implementations.

arc4 is 67 % faster than the de facto PyCrypto library. Also, 1889 % faster than pure-Python rc4 library.

arc4 0.332659006119
PyCrypto 0.544879198074
rc4 6.60579204559

The whole benchmark code is in ./


Install from PyPI:

pip install arc4

Or clone the repo and do install:

git clone
cd arc4
python install


from arc4 import ARC4

arc4 = ARC4('key')
cipher = arc4.encrypt('some plain text to encrypt')

Because RC4 is a stream cipher, you must initialize RC4 object in the beginning of each operations.

arc4 = ARC4('key')


python -m unittest discover


This software is under the MIT License.

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Files for arc4, version 0.0.2
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Filename, size arc4-0.0.2-cp36-cp36m-macosx_10_14_x86_64.whl (5.4 kB) File type Wheel Python version cp36 Upload date Hashes View hashes
Filename, size arc4-0.0.2.tar.gz (3.7 kB) File type Source Python version None Upload date Hashes View hashes

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