Re: Intercepting Microsoft wireless keyboard communications

2009-07-17 Thread travis+ml-cryptography
On Tue, Dec 11, 2007 at 02:01:03PM -0500, j...@tla.org wrote: How many bits (not just data, also preamble/postamble, sync bits, etc.) is the keyboard sending for each keystroke anyway? FWIW, it is likely sending keyboard scan codes: http://en.wikipedia.org/wiki/Scancode It doesn't send the

Re: Intercepting Microsoft wireless keyboard communications

2007-12-14 Thread Peter Gutmann
James A. Donald [EMAIL PROTECTED] writes: At every block boundary, keyboard transmits a special signal in the clear that signifies block boundary. Any time that no key has been pressed for a while, then when a key is finally pressed, keyboard transmits a bunch of no- ops sufficient to ensure

Re: Intercepting Microsoft wireless keyboard communications

2007-12-13 Thread Taral
On 12/10/07, Steven M. Bellovin [EMAIL PROTECTED] wrote: Believe it or not, I thought of CFB... What about PCFB to get around the block issue? I remember freenet using it that way... -- Taral [EMAIL PROTECTED] Please let me know if there's any further trouble I can give you. -- Unknown

Re: Intercepting Microsoft wireless keyboard communications

2007-12-13 Thread James A. Donald
Steven M. Bellovin wrote: Believe it or not, I thought of CFB... Sending keep-alives will do nasties to battery lifetime, I suspect; most of the time, you're not typing. As for CFB -- with a 64-bit block cipher (you want them to use DES? they're not going to think of anything different),

Re: Intercepting Microsoft wireless keyboard communications

2007-12-11 Thread Leichter, Jerry
| Exactly what makes this problem so difficult eludes me, although one | suspects that the savage profit margins on consumables like | keyboards and mice might have something to do with it. | | It's moderately complex if you're trying to conserve bandwidth (which | translates to power) and

Re: Intercepting Microsoft wireless keyboard communications

2007-12-11 Thread James A. Donald
Steven M. Bellovin wrote: It's moderately complex if you're trying to conserve bandwidth (which translates to power) and preserve a datagram model. The latter constraint generally rules out stream ciphers; the former rules out things like encrypting the keystroke plus seven random bytes with a

Re: Intercepting Microsoft wireless keyboard communications

2007-12-11 Thread Steven M. Bellovin
On Tue, 11 Dec 2007 13:49:19 +1000 James A. Donald [EMAIL PROTECTED] wrote: Steven M. Bellovin wrote: It's moderately complex if you're trying to conserve bandwidth (which translates to power) and preserve a datagram model. The latter constraint generally rules out stream ciphers; the

RE: Intercepting Microsoft wireless keyboard communications

2007-12-09 Thread Ian Farquhar (ifarquha)
When I looked at this circa 2001-2002, for another company, other 27MHz keyboards didn't even bother to encrypt. Most of the data was sent in the clear, with neither encryption nor robust authentication. Exactly what makes this problem so difficult eludes me, although one suspects that the