home *** CD-ROM | disk | FTP | other *** search
- Xref: sparky sci.crypt:3153 comp.security.misc:1201
- Path: sparky!uunet!gatech!prism!gs26
- From: gs26@prism.gatech.EDU (Glenn R. Stone)
- Newsgroups: sci.crypt,comp.security.misc
- Subject: Re: "Sneakers" -- action/adventure movie about Cryptography
- Message-ID: <67830@hydra.gatech.EDU>
- Date: 8 Sep 92 19:03:10 GMT
- References: <1992Sep1.060412.14956@fig.citib.com> <naran.715539174@sfu.ca> <1992Sep3.185207.29154@news.eng.convex.com> <715637499@romeo.cs.duke.edu>
- Reply-To: glenn.stone@eas.gatech.edu
- Followup-To: sci.crypt
- Organization: The Group W Bench
- Lines: 31
-
- In <715637499@romeo.cs.duke.edu> trt@duke.cs.duke.edu (Tom Truscott) writes:
-
- >>>Anyways, one-time pads are really effective in short
- >>>messages and are reasonably secure on larger documents.
-
- >Arguably this is backwards. As suggested in "Codebreakers",
- >if I suspect that a "yes" or "no" decision is forthcoming, and I
- >intercept a 3 character long message, I can make a reasonable
- >guess as to the message's contents.
-
- nope, 'cause even the book I have on crypto written for 10-year-olds
- says to pad your messages out to groups of five....
-
- sotha ttraf fican alysis isnot asbig athre atasi tcoul dbexx
-
- >More generally, "traffic analysis" is still a threat. So some systems
- >send continuously, just sending nulls or-ed with the pad
- >(== the pad itself) when there is no real traffic.
-
- This is doubly true, however. Everybody who's been around knows that when
- there are pizza delivery trucks headed for Foggy Bottom, Something Big is
- going down.... a very simple "traffic analysis".
-
- Anything remotely resembling good code won't reveal the actual number of
- characters in the message exactly; really good stuff, a la above, sends
- synchronously and uses framing characters or some such... on the other
- hand, if you stumble onto something sending async, you can always tell
- when something's going on when the message traffic goes way up... ;)
-
- -- Glenn R. Stone (glenn.stone@eas.gatech.edu)
- Nazi conservative Quayle NSA coverup watergate CIA breakin nuclear gun drugs
-