From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,9d00a7db22818139 X-Google-Attributes: gid103376,public X-Google-Thread: fb57f,9d00a7db22818139 X-Google-Attributes: gidfb57f,public X-Google-ArrivalTime: 2001-03-04 13:10:46 PST Path: supernews.google.com!sn-xit-03!supernews.com!nntp.cs.ubc.ca!newsfeed.direct.ca!look.ca!newsfeed.icl.net!dispose.news.demon.net!news.demon.co.uk!demon!extropy.demon.co.uk!not-for-mail From: "Julian Morrison" Newsgroups: comp.lang.ada,sci.crypt Subject: Re: Arcfour in Ada Date: Sun, 04 Mar 2001 21:08:09 +0000 Message-ID: <983740057.8037.0.nnrp-13.9e98cc46@news.demon.co.uk> References: <983158039.27320.0.nnrp-08.9e98cc46@news.demon.co.uk> <3A9ADBAE.EFF0B8AC@multiweb.nl> <3A9B242E.D7D177A8@earthlink.net> <3AA239E8.BB9AA911@multiweb.nl> NNTP-Posting-Host: extropy.demon.co.uk X-NNTP-Posting-Host: extropy.demon.co.uk:158.152.204.70 X-Trace: news.demon.co.uk 983740057 nnrp-13:8037 NO-IDENT extropy.demon.co.uk:158.152.204.70 X-Complaints-To: abuse@demon.net User-Agent: Pan/0.9.3 (Unix) Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Tranfer-Encoding: 8bit X-No-Productlinks: Yes Xref: supernews.google.com comp.lang.ada:5415 sci.crypt:18872 Date: 2001-03-04T21:08:09+00:00 List-Id: "Thomas Boschloo" wrote: > But I figure that Arcfour has some overhead because of the extra keys > you have to send :-) You don't send extra keys, you send one partial key, you complete it with a new IV each time it's used, and prepend the IV to the message. > Funny that DoD doesn't have Rijndael in Ada, as they developed Ada in > the first place :-P I had a large interest in Ada because the design > philosophy appealed to me, but I figured it would be largely 'dead' by > now and replaced by C++ and Java :-( I don't like C++, it's a mess. There is Rijndael in Ada, available from the Adapower site. Unlikely to be guv'mint code - bureaucrats are born with "security through obscurity" hardwired into the soul. > To Julian (if he still frequents this newsgroup, my reply is a bit > overtime) I do :-) > , I figured you could just use one of those 16 bytes as a > 'length' field. You would even keep 4 bits of that 'octet' for other > purposes or future additions! The overhead doesn't seem as bad as you > presented at first (I seem to remember somehow that you thought it was > 64 bytes, I might be mistaken). I can switch to Rijndael easily, since there's Ada code for it, but it's fiddly and more bother than I care for, and the potential gain isn't great enough to justify the hassle. > And you wouldn't have the 'key' overhead in Arcfour (no idea how big > that would be in the long run). There isn't any, really, at least not any I wouln't need just as bad with Rijndael. > Here are some RFC's you might consider reading (if you hadn't done so > already): > > RFC 793 (TCP), 1122 (fixes), 1323 (extensions) => TCP protocol RFC 768 > => UDP (very easy and simple to understand) RFC 791 => IP version 4 RFC > 1883 => IP version 6 (longer addresses for the future) > > Protocols like TCP/UDP are layered on IP and the RFC's can tell you the > sizes of the datagrams you can send with them. Thanks for that info :-)