How to decrypt a hexadecimal value, having a key, using the DES algorithm?

Question

Information Security

Given a pair of a sixteen-byte value and its key, encrypted using the DES algorithm in ECB mode. How to decrypt the original value? Tell me the algorithm and what to read on this topic. Also interested in TripleDES in CBC mode.

Answer 1

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

Answer 2

Again kindergarten for a walk. http://ru.wikipedia.org/wiki/DES