hg wrote: > Ning wrote: > >> I'm trying to write an IM client which sends encrypted messages to the >> server. I tried to use pycrypto library, but when I came to 3DES >> cypher I was confused about the keysize to use. In the standard it >> said that it should be either 112 bits or 168 bits, whereas it's 16 >> bytes or 24 bytes in pycrypto. If I use 16 bytes key to encrypt and >> send this key to the server which is expecting a 112 bits key, there'll >> be a problem. How I should solve this? > > You need to account for the parity bits: > http://en.wikipedia.org/wiki/Triple_DES > > > If that may reassure you ;-) I use PyCrypto to "talk" to smart cards > without any problem. > > hg
PS: as stated in the wiki, I would seriously consider AES as it is safer / faster / supported by pycrypto hg -- http://mail.python.org/mailman/listinfo/python-list