Re: [Cryptography] Crypto being blamed in the London riots.

2011-08-10 Thread Sampo Syreeni

On 2011-08-09, Nick wrote:

However, as was pointed out then, apparently the encryption is to  
from RIM's servers, not the recipient. So RIM have access to all the 
'secret' messages. I expect GCHQ  the Met will make sure said systems 
are patched in to their surveillance programme in no time.


Thus, why not turn the Trusted Computing idea on its head? Simply make 
P2P public key cryptography available to your customers, and then bind 
your hands behind your back in an Odysseian fasion, using hardware 
means? Simply make it impossible for even yourself to circumvent the 
best cryptographic protocol you can invent, which you embed in your 
device before ever unveiling it, and then just live with it?


Unfortunately the present climate in England is such that I can't 
imagine such measures being anything but lauded.


Thus the need for credible precommitment, TC-style, at the hardware 
level..

--
Sampo Syreeni, aka decoy - de...@iki.fi, http://decoy.iki.fi/front
+358-50-5756111, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2
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Re: [Cryptography] Crypto being blamed in the London riots.

2011-08-10 Thread Perry E. Metzger
On Wed, 10 Aug 2011 11:53:11 -0400 Ken Buchanan
ken.bucha...@gmail.com wrote:
 On Tue, Aug 9, 2011 at 8:02 PM, Sampo Syreeni de...@iki.fi wrote:
  Thus, why not turn the Trusted Computing idea on its head? Simply
  make P2P public key cryptography available to your customers, and
  then bind your hands behind your back in an Odysseian fasion,
  using hardware means? Simply make it impossible for even yourself
  to circumvent the best cryptographic protocol you can invent,
  which you embed in your device before ever unveiling it, and then
  just live with it?
 
 
 Why not, indeed...
 
 Because no regulatory regime in the world would allow this.

Funny, that, since Sampo's proposal is more or less how Blackberry
chat actually works. (Various previous posters had the details wrong.)
Also all blackberry corporate services work without RIM having any
access to the content -- they only get access to email for individual
users for whom they terminate the encrypted tunnel.

Perry
-- 
Perry E. Metzgerpe...@piermont.com
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Re: [Cryptography] Crypto being blamed in the London riots.

2011-08-10 Thread Perry E. Metzger
On Wed, 10 Aug 2011 11:59:53 -0400 John Ioannidis j...@tla.org wrote:
 On Tue, Aug 9, 2011 at 8:02 PM, Sampo Syreeni de...@iki.fi wrote:
 
  Thus, why not turn the Trusted Computing idea on its head? Simply
  make P2P public key cryptography available to your customers, and
  then bind your hands behind your back in an Odysseian fasion,
  using hardware means? Simply make it impossible for even yourself
  to circumvent the best cryptographic protocol you can invent,
  which you embed in your device before ever unveiling it, and then
  just live with it?
 
 
 Customers? There is no profit in any manufacturer or provider to
 build that kind of functionality.

Blackberry already more or less has that functionality, which
disproves your hypothesis.

Perry
-- 
Perry E. Metzgerpe...@piermont.com
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Re: [Cryptography] Crypto being blamed in the London riots.

2011-08-10 Thread Steven Bellovin
On Aug 10, 2011, at 12:19 53PM, Perry E. Metzger wrote:

 On Wed, 10 Aug 2011 11:59:53 -0400 John Ioannidis j...@tla.org wrote:
 On Tue, Aug 9, 2011 at 8:02 PM, Sampo Syreeni de...@iki.fi wrote:
 
 Thus, why not turn the Trusted Computing idea on its head? Simply
 make P2P public key cryptography available to your customers, and
 then bind your hands behind your back in an Odysseian fasion,
 using hardware means? Simply make it impossible for even yourself
 to circumvent the best cryptographic protocol you can invent,
 which you embed in your device before ever unveiling it, and then
 just live with it?
 
 
 Customers? There is no profit in any manufacturer or provider to
 build that kind of functionality.
 
 Blackberry already more or less has that functionality, which
 disproves your hypothesis.
 
More precisely, Blackberry email is encrypted from the recipient's
Exchange server to the mobile device.

The scenario is corporate email; the business case is that RIM could
claim that they *couldn't* read the email; they never had it in the
clear.  However, that's only true for that service.  For personal
Blackberries, there is no corporate-owned server doing the encryption.

The service in question here, though, is Blackberry Messenger.  There
seems to be some confusion about whether or not such messages are
encrypted, and if so under what circumstances.  One link
(http://www.berryreview.com/2010/08/06/faq-blackberry-messenger-pin-messages-are-not-encrypted/)
 says that they're not, in any meaningful form.  More
authoritatively, 
http://web.archive.org/web/20101221211610/http://www.cse-cst.gc.ca/its-sti/publications/itsb-bsti/itsb57a-eng.html
says that they aren't.

The most authoritative source is RIM itself.  P 27 of
http://docs.blackberry.com/16650/ confirms the CSE document.

Looking at things more abstractly, there's a very difficult key 
management problem for a decentralized, many-to-one encryption service.
Here, you're either in CA territory or web of trust territory.  In
this case, are the alleged perpetrators of the riots careful enough
about to which keys they're sending the organizing messages?  If
the pattern is anything like Facebook friending, I sincerely doubt
it.


--Steve Bellovin, http://www.cs.columbia.edu/~smb





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[Cryptography] Crypto being blamed in the London riots.

2011-08-09 Thread Perry E. Metzger
Quoting from the New York Times:

  David Lammy, Britain's intellectual property minister, also called
  for a suspension of Blackberry's encrypted instant message service.
  Many rioters, exploiting that service, had been able to organize mobs
  and outrun the police, who were ill-equipped to monitor it. It is
  unfortunate, but for the very short term, London can't have a night
  like the last, Mr. Lammy said in a Twitter post.

  Officials at Research in Motion, the corporate parent of Blackberry,
  declined to comment on whether the service would be suspended. But
  the company, based in Waterloo, Ontario, issued a statement saying:
  We feel for those impacted by recent days' riots in London. We have
  engaged with the authorities to assist in any way we can.

http://www.nytimes.com/2011/08/10/world/europe/10britain.html

-- 
Perry E. Metzgerpe...@piermont.com
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Re: [Cryptography] Crypto being blamed in the London riots.

2011-08-09 Thread Nick
 Quoting from the New York Times:
 
   David Lammy, Britain's intellectual property minister, also called
   for a suspension of Blackberry's encrypted instant message service.
   Many rioters, exploiting that service, had been able to organize mobs
   and outrun the police, who were ill-equipped to monitor it.

IIRC this came up last year when a Middle Eastern country (I forget 
which) were threatening to not let RIM operate unless they could 
intercept blackberry messages.

However, as was pointed out then, apparently the encryption is to  
from RIM's servers, not the recipient. So RIM have access to all the 
'secret' messages. I expect GCHQ  the Met will make sure said 
systems are patched in to their surveillance programme in no time.

Unfortunately the present climate in England is such that I can't 
imagine such measures being anything but lauded.


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