Chilkat2-Python

ARC4 Encryption (ARCFOUR)

See more Encryption Examples

ARC4 (ARCFOUR) encryption. The Chilkat encryption component supports the ARC4 streaming encryption algorithm. Chilkat2-Python

import chilkat2

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

crypt = chilkat2.Crypt2()

# Set the encryption algorithm = "arc4"	
crypt.CryptAlgorithm = "arc4"

# KeyLength may range from 1 byte to 256 bytes.
# (i.e. 8 bits to 2048 bits)
# ARC4 key sizes are typically in the range of 
# 40 to 128 bits.
# The KeyLength property is specified in bits:
crypt.KeyLength = 128

# Note: The PaddingScheme and CipherMode properties
# do not apply w/ ARC4.  ARC4 does not encrypt in blocks --
# it is a streaming encryption algorithm. The number of output bytes
# is exactly equal to the number of input bytes.

# EncodingMode specifies the encoding of the output for
# encryption, and the input for decryption.
# It may be "hex", "url", "base64", or "quoted-printable".
crypt.EncodingMode = "hex"

# Note: ARC4 does not utilize initialization vectors.  IV's only
# apply to block encryption algorithms.  

# The secret key must equal the size of the key.
# For 128-bit encryption, the binary secret key is 16 bytes.
keyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"
crypt.SetEncodedKey(keyHex,"hex")

# Encrypt a string...
# The output length is exactly equal to the input.  In this
# example, the input string is 44 chars (ANSI bytes) so the
# output is 44 bytes -- and when hex encoded results in an
# 88-char string (2 chars per byte for the hex encoding).
encStr = crypt.EncryptStringENC("The quick brown fox jumps over the lazy dog.")
print(encStr)

# Now decrypt:
decStr = crypt.DecryptStringENC(encStr)
print(decStr)