- From: Richard Barnes <rlb@ipv.sx>
- Date: Thu, 14 Mar 2013 13:19:19 -0400
- To: Peter Waher <Peter.Waher@clayster.com>
- Cc: Matt Miller <mamille2@cisco.com>, Stephen Williams <sdw@lig.net>, XMPP Standards <standards@xmpp.org>, "public-exi@w3.org" <public-exi@w3.org>, "Joachim Lindborg (joachim.lindborg@sust.se)" <joachim.lindborg@sust.se>, "xmpp@ietf.org" <xmpp@ietf.org>, "mact-usa@att.net" <mact-usa@att.net>, FABLET Youenn <Youenn.Fablet@crf.canon.fr>
- Message-ID: <CAL02cgSFsW1ccdqb2tq5bCE_SbwdmOLVf81+v07ZOoQWFvhk6Q@mail.gmail.com>
I think you'll find that if you try to compress after encrypting, you're going to have a bad time. Exi1(Encrypt(Xml)) is not going to buy you anything besides some wasted cycles. --Richard On Thu, Mar 14, 2013 at 11:25 AM, Peter Waher <Peter.Waher@clayster.com>wrote: > Dear Matt > > I just became aware of your IETF draft for XMPP end-to-end encryption. It > looks very promising. > http://tools.ietf.org/html/draft-miller-xmpp-e2e-05 > > We work with sensor network architecture over XMPP, and some (but not all) > applications require end-to-end encryption, so we want to look at this > extension. > > At the same time, compression is a vital issue, since many sensors have > limited memory. Therefore, we are working with an effort to include the use > of EXI in XMPP. (See attached documents.) One important aspect to know, > when including EXI into XMPP, is that packets cannot be binary copied when > the server relays the information. The packets have to be decompressed, and > re-compressed if both peers have EXI-compressed channels. This requires EXI > to be applied after any message encryption transformation: > Exi1(Encrypt(Xml)). Server then relays Exi2(DeExi1(Exi1(Encrypt(Xml)))) = > Exi2(Encrypt(Xml)) to the second peer. > > The problem with this is that EXI does not do very well with > base64-encoded binary data. Size(Exi(Base64(Bin))) would approximately be > equal to Size(Bin). EXI would be able to cut the added length imposed by > the base64 encoding, due to its limited character set. > > It would be nice with an end-to-end encryption method over XMPP that would > also be able to take into account EXI compression of XML stanzas. > > If you have time, any comments would be appreciated, > > Sincerely, > Peter Waher > > > -----Original Message----- > From: Peter Saint-Andre [mailto:stpeter@stpeter.im] > Sent: den 14 mars 2013 11:57 > To: Peter Waher > Cc: Joachim Lindborg (joachim.lindborg@sust.se); Matt Miller > Subject: Re: XMPP stanza encryption > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 3/14/13 10:53 AM, Peter Waher wrote: > > Hello Peter > > > > Do you participate in this work? > > http://tools.ietf.org/html/draft-miller-xmpp-e2e-05 > > Only indirectly, by chatting once in a while with Matt Miller (cc'd). > > Peter > > - -- > Peter Saint-Andre > https://stpeter.im/ > > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG/MacGPG2 v2.0.18 (Darwin) > Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ > > iQIcBAEBAgAGBQJRQeU7AAoJEOoGpJErxa2p6y8P/jHGYyu4DxkpgjIlxIyP/ROF > KfHkaOQ9kzVqEP+fWzajYK9MW8NzaGkF8w8L43o6sXbbFxtmIIZgiUpG2G9uMg8w > 6yBrR+JbDHTSpq9bEjrA55jKjVHAQjXUpEvT71zvpqpMa8GU4mM8oLad/ETkg0QI > YJsfGal66rSA9ZXdr78U8C7pOIFNhgV6SdLHUq1TF9jpXghXAN7bvRtGgPJk1jea > QN45YW//Zq9NMK0KK+MmgmK+JPsb3/MM7uFSp90FTUQY7/iF1ngjoA/3tqOiaQMW > E8Q40DIRXjzXHiiKMTwle7Q1zLP1Jm86aJp8iScsRy0OxNSH9s5NQ7AaD5ZTl/BL > 64oiA9dLpcc/RZf/7kWDp7D7zEHli2yJG+tO0gagJHqfOt8R/WCeJR10hrBQ76rj > JbwBqWwJRMrY1SnqlntBfhMklC7ZzkuXMn75QtqkQlflJ//6v53AcCglZBLpIurT > xaHHO6IUvsjOvoRov1m65HTtOb9qwepPOJ4mo78bRure2HgBKBCNZRyRZPy6s8lU > OuXqciZjDmKxMlO/A4nGMu2OP7ZcrWo58t1p7sckbC4q4YDoVBTPvA3KlcQB1kPm > YlIGtme+MEVHVm6LvJq+Gm5C8cvXM1nB2lmHvcEWJfcSVkT03EGRKLNZm4aWchMN > 4s30FwvW1t9EukM+RGy6 > =EN9u > -----END PGP SIGNATURE----- > > _______________________________________________ > xmpp mailing list > xmpp@ietf.org > https://www.ietf.org/mailman/listinfo/xmpp > >
Received on Thursday, 14 March 2013 21:36:49 UTC