[18687] in cryptography@c2.net mail archive
Re: SecurID and garage door openers
daemon@ATHENA.MIT.EDU (Joseph Ashwood)
Tue Oct 18 17:09:20 2005
X-Original-To: cryptography@metzdowd.com
X-Original-To: cryptography@metzdowd.com
From: "Joseph Ashwood" <ashwood@msn.com>
To: <cryptography@metzdowd.com>
Date: Tue, 18 Oct 2005 14:01:42 -0700
----- Original Message -----
From: "Travis H." <solinym@gmail.com>
Subject: SecurID and garage door openers
> Similarly, how do those garage door openers with "rolling codes" work,
> given that the user may have pressed the button many times
> accidentally while out of range of the receiver?
My understanding is that since it is a purely monotonic counter it is plenty
possible to do one of two things:
send {counter, data} instead of {data}, receiver stores last counter to
avoid replays
have the receiver just keep counting forward for a while (not a good idea
> Is there any interest in reviewing the security of consumer-level
> devices?
I'd be willing to take a look at the protocol, but dissection is not my
specialty.
> PS: How many cypherpunks does it take to open a garage door?
> http://www.cap-lore.com/Garage/
Currently, not very many, with proper designs openly published, not very
many because not very many companies will use it. However, it could be a
useful way for some cipherpunks to make some extra money. Anyone else up for
it? and how about the car alarm?
Joe
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