Re: some issues regarding OFB and CFB mode
Paul Lambert <[email protected]>
| Newsgroups | gmane.comp.python.cryptography |
|---|---|
| Message-ID | <[email protected]> |
But why should a stream cipher ever be used? Yes, a few bytes can be saved (no padding), but the issues of maintaining nonce/IV uniqueness in a distributed environment add both risk and complexity to a system. Bad ciphers and modes should not be included in a crypto library without adequate justification. Just an opinion ... Paul > -----Original Message----- > From: Christian Krause [mailto:[email protected]] > Sent: Wednesday, October 23, 2002 3:16 PM > To: [email protected] > Subject: some issues regarding OFB and CFB mode > > > Hi, > > I found some missing features in the current implementation > of pycrypto: > > 1. > The modes OFB and CFB should work as real stream ciphers. There > is no need to depend on the BLOCKSIZE or the segment_size. > > 2. > The OFB mode should work with different segement_sizes (and not only > with the blocksize). > > Is there a reason why the current implementation doesn't > implement these > features? > > Nevertheless I've made a patch to allow the OFB mode to work > as a real stream > cipher so you can encrypt strings with every length. > > https://sourceforge.net/tracker/index.php?func=detail&aid=6265 87&group_id=20937&atid=320937 If I have time, I'll create the according patch for CFB and for 2. regards, christian