using DES/3DES with python

ron picture ron · Mar 12, 2010 · Viewed 42.4k times · Source

what is the best module /package in python to use des /3des for encryption /decryption. could someone provide example to encrypt data with des/3des on python.

Answer

Leo picture Leo · Mar 13, 2010

pyDes can be used for both, DES and 3DES. Sample usage:

from pyDes import *

data = "Please encrypt my data"
k = des("DESCRYPT", CBC, "\0\0\0\0\0\0\0\0", pad=None, padmode=PAD_PKCS5)
d = k.encrypt(data)
print "Encrypted: %r" % d
print "Decrypted: %r" % k.decrypt(d)
assert k.decrypt(d, padmode=PAD_PKCS5) == data

An alternative is the Chillkat Python Encryption Library which supports a lot of encryption algorithms (including DES & 3DES), but it is not free. Sample usage:

crypt.put_CryptAlgorithm("des")
crypt.put_CipherMode("cbc")
crypt.put_KeyLength(64)
crypt.put_PaddingScheme(0)
crypt.put_EncodingMode("hex")
ivHex = "0001020304050607"
crypt.SetEncodedIV(ivHex,"hex")
keyHex = "0001020304050607"
crypt.SetEncodedKey(keyHex,"hex")
encStr = crypt.encryptStringENC("The quick brown fox jumps over the lazy dog.")
print encStr
decStr = crypt.decryptStringENC(encStr)
print decStr

Anyway, I hope that you are aware that neither DES nor 3DES are considered paritcularly safe nowadays, there are many better alternatives (AES in the first place if you want to stick to standards, or Twofish, Blowfish, etc...)