Challenge to TCPA/Palladium detractors
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal: Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications. In other words, allow a distributed network application to create a "closed world" where it has control over the data and no one can get the application to "cheat". IMO this is clearly the real goal of TCPA and Palladium, in technical terms, when stripped of all the emotional rhetoric. As I posted previously, this concept works especially well for open source applications. You could even have each participant compile the program himself, but still each app can recognize the others on the network and cooperate with them. And this way all the participants can know that the applications aren't doing anything different than what they claim. This would be a very powerful capability with many uses that you might find both good and bad. I posted a long message earlier with three examples of privacy-oriented applications: secure game playing, anonymous P2P networking, and untraceable digital cash. In addition it can be used for DRM, restricting access to sensitive business or government data, and similar applications. For those of you who claim that such a technology is not necessarily objectionable in itself, but that the implementations in TCPA and Palladium are flawed, please explain how you could do it better. How can you maximize user control and privacy and minimize the potential for government or corporate takeovers? In other words, what *exactly* is wrong with the way that TCPA and Palladium choose to do things? Can you fix those problems and still achieve the basic goal, above?
On Wed, 7 Aug 2002, AARG! Anonymous wrote:
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal:
Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications.
In other words, allow a distributed network application to create a "closed world" where it has control over the data and no one can get the application to "cheat". IMO this is clearly the real goal of TCPA and Palladium, in technical terms, when stripped of all the emotional rhetoric.
Yes, this is a major research project in many universities. Nobody has a complete solution for the general case but some solutions for specific cases. IBM and Certicom both have hardware computation platforms that allow a single company to verify its stuff is secure on remote platforms, but the remote platform is under the control of the company, it's not a generic PC that any consumer owns. Personally I think it's impossible. Once the data is in the clear in some form it can be copied to some other form. You can't stop someone from cheating if you want them to get access to data.
For those of you who claim that such a technology is not necessarily objectionable in itself, but that the implementations in TCPA and Palladium are flawed, please explain how you could do it better. How can you maximize user control and privacy and minimize the potential for government or corporate takeovers?
In other words, what *exactly* is wrong with the way that TCPA and Palladium choose to do things? Can you fix those problems and still achieve the basic goal, above?
No, it's not possible to ship data around and let anyone see it *and* prevent it from being copied. What you can do is create specific environments for specific applications, and there are already solutions available for those purposes. The problem with TCPA and Palladium is attempting to make it generic. If one person controls all computers, then the specific solution becomes possible. But it just happens that most of us don't like the idea of one person controling all computers. Patience, persistence, truth, Dr. mike
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal: Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications. [...] You could even have each participant compile the program himself, but still each app can recognize the others on the network and cooperate with them.
Unless the application author can predict the exact output of the compilers, he can't issue a signature on the object code. The compilers then have to be inside the trusted base, checking a signature on the source code and reflecting it somehow through a signature they create for the object code. --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com
"AARG!Anonymous" wrote:
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal:
Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications.
That is frightfully underspecified. Creating such a system could be very easy or very hard, depending on what range of policies is to be supported, and depending on what your threat model is. At one extreme I might trust an off-the-shelf PC if it were booted from CD by trusted parties in a TEMPEST-shielded room surrounded by armed guards. At the other extreme, making tamper-proof hardware to face unlimited threats is very, very hard -- most likely outside the "PC" price range for the foreseeable future.
In other words, allow a distributed network application to create a "closed world" where it has control over the data and no one can get the application to "cheat". IMO this is clearly the real goal of TCPA and Palladium, in technical terms, when stripped of all the emotional rhetoric.
Well, the "technical terms" are not and should not be the sole focus of the current discussion. There are other questions such as -- what range of policies should be supported -- who gets to set the policy -- who decides who trusts whom -- etc. etc. etc. I agree that there has been too much ad-hominem sewage and emotional rhetoric mixed in with the valid arguments recently.
Anonymous wrote:
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal:
Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications.
On balance, I suspect I would say that this is not a desirable goal. I can see that it has its uses, but I think they are outweighed by the fact that I would no longer have complete control of my own computer. "Complete control" means being able to lie if I choose to. If it is coming anyway, I think the harm would be mitigated if two features were provided: Firstly, there should be no discrimination between operating systems. I want to be able to run a version of Linux (or any other operating system) that makes use of the hardware security features. If I built my own operating system, people might not trust it as much as operating systems that are better known. Fine, that's the way trust works. But I still want my operating system to be able to use the hardware. The signatures would be for "program foo running on PeteOS", so making clear to the relying party that the signature is only as good as my operating system's security. Secondly, there should be no discrimination between applications. I should be able to write a DRM system that works in the same way as any RIAA-approved one. Of course people may not trust my system, that's their choice. I'd be interested to know what the experts think -- will this functionality be available to me? -- Pete --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com
On Wed, Aug 07, 2002 at 12:50:29PM -0700, AARG!Anonymous wrote:
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal:
Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications.
The TCPA/Palladium folks have been working on this for apparently around 5 years. We don't yet have a complete definition of what Palladium is, but anyway...
Can you fix those problems and still achieve the basic goal, above?
It may be that some interesting hardware, TOR and OS design changes could be added which could change the balance. Other aspects are as John Denker said more to do with who will control keys and policies and how much effective user control and choice remains over these policies. My initial thoughts were around hardware and TOR enforced in-flow and out-flow control to trusted agents. This idea was seeded by the smart-card setting of Stefan Brands digital credentials. (Read [1] if you are interested, it's a very clever idea, related to observers in cryptogaphic protocols in hardware settings). Briefly the observer in Brands protocol (and observers have been proposed in other cryptogaphic literature also) tackles an analogous problem with cryptographic assurance in the special purpose case of privacy preserving credentials, e-cash and other applications that can be built from those techniques. You have a tamper-resistant smart card. However the user can't reasonably audit the behavior of the smart-card processor because it intentionally hides it's keys from the user. Even if the source is published, audited, and claims and endoresments about the hardware made, the user still can't easily audit or reasonablly trust what is actually in his smart-card. The tamper-resistant smart card is somewhat related to the crypto functions of the SCP in Palladium or the TPM in TCPA, but the observer approach may offer lessons for TCPA/Palladium in general at higher levels. The tamper-resistant smart card is considered untrusted and hostile to user privacy. The tamper-resistant smart card processor and software is acting in the interests of the credential issuer / ecash issuer to prevent the user double-spending coins (*) / using credentials more times than allowed. The user has a general purpose computer running software he can completely audit, control observe running and modify. The smart-card has to make all communications with ecash acccepting merchants, certificate verifiers etc via the general purpose computer the smart-card is connected to. The general purpose computer implements the observer protocols. The smart-card setting variant of Brands protocol cryptographically assures 2 things: - the ecash issuer / credential CA can be assured that the user can not double spend (or in general violate other properties mediated by the tamper-resistant smart card) - the user is cryptographically assured that the smart-card can not invade his privacy. This works because the in-flows and out-flows to the smart card are hardware assured to pass via the general purpose computer, auditable, use published formats and are cryptographically blinded, to the extent of optimally frustrating even subliminal channels, via steganography and the like. In the same way that TCPA/Palladium are a generalisation of the dongle concept, this would be a generalisation of the cryptographic concept of observers. So for your convenience here's a cut and paste of that initial thought on applying the observer principle to general purpose TCPA/Palladium platform from the previous message with subject "Palladium: hardware layering model": I wrote in that message: | One idea I think would be interest is as follows: | | - the TOR (which lives in ring-0) _could_ be used together with the OS | to force all trusted-agent in-flows and out-flows (network traffic) to | go through code under supervisor mode control. | | I don't think this is likely in the current design; but this change | would be an improvement: | | - it would at least allow user audit and control of in-flows and | out-flows; | | - the user could block suspicious phone-home information out-flows, | | - the user could read out-flows and demand un-encrypted documented | formats, or if encrypted, encrypted with keys the supervisor mode gets | copies of. | | - similarly in-flow control is interesting, because with no in-flows a | trusted agent could be more liberally allowed to make out-flows (if it | has no input knowledge, and is in a code compartment, and the user | gave it no sensitive it doesn't know anything to leak.) this is not a fully fleshed out idea as I only thought of it yesterday, and can't fully analyse it's implications because we don't yet know proper details of what Palladium hardware is, nor how microsofts proposed Palladium enhanced windows would be implemented on that hardware. Adam (*) Actually he will still be caught and identified with Brands ecash protocols when the coins are deposited if he does double-spend coins after breaking hardware tamper-resistance, but that is a level of detailed not central to this discussion. [1] "A Technical Overview of Digital Credentials", Stefan Brands, Feb 2002, to appear in International Journal on Information Security. See Section 8. http://www.xs4all.nl/~brands/overview.pdf --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com
You can only do this if you can trust the hardware. As long as any potential untrustworthy folks have access to that hardware, it cannot be done. It is possible to do the rest of this if you manage to secure the machines from any other kinds of access by disabling all services other than that particular p2p (to prevent remote access overflows from insecure applications). If you see the network problem as a multi-ended VPN, that's the next part. But I do not see any way for any member of the network to certify that any other node is running exactly the same software, unless all nodes restrict access to the hardware and have an external certification process. If anyone anywhere can grab the software - binary or source and join the network while still having hardware access, all bets are off. The only thing the other nodes can certify is that the crypto signatures are right, and that the protocol is the same. But even if you sign the binaries, you don't know that the thing at the other end has the signature it just sent you. You can try to make things complex such as pushing binaries to the other node and having them run there, but you don't know if you're inside a VMware box, or Bochs emulator, or a real machine. Even if you can certify that the application does what you think it does, you can't ceritfy that the operating system or the hardware isn't going to do anything else. End of story. Can't be done so long as anyone other than you has root on the machine, or has physical access. Hence you need to buttplug the hardware and make it difficult to modify. Even so, you don't have any idea of if that CPU really is what it says it is, or that the hardware will do what you think it will do. Hardware can be replaced or patched with things that can look like the original, or things that at some opportune moment interrupt and switch out that hardware, then get full access to all the ram. No, I couldn't afford such hardware mods. But say someone that has enough money to own a DVD pressing factory certainly can afford the R&D. In the end TCPA/Palladium will be broken. Just the USG kept pushing single DES until even a bit after the DES cracker got built. I've no problem with that, nor the fact the RIAA/MPAA want to protect their warez - if they get that oppresive, I won't be buying it, and I'm positive that others won't either... In the end, they'll just be burning a lot of money and find out that they'll go broke. Ironic? Yup. As long as it's a free market, they'll fry for pissing off their consumers. I do have a problem with having spyware forced down my machines by John Law. Intel wants to put Pd compliant chips in their mobo's, fine, I won't buy their hardware -- or if I do, I'll be sure to reflash the BIOS to a slightly different enough version without signatures to force the Pd chip to shut down... If it won't let me, their loss. There's still AMD. AMD joins intel? Fuck x86, there's still Sun, and Apple. The only way that Pd will be successful is if every hardware manufacturer is forced by law to include it. And I've no problem with MSFT making their software oppresive, they're just digging their own graves, I'll applaud as they sink in to the bog. Fuck'em. They're extinct. Long as the motherboard will let me boot whatever OS I want, long as Kongress keeps their paws out of my machine and doesn't extract a tax to pay the losers for their "losses", MSFT, Intel, MPAA, RIAA can do whatever they want. And no, I don't believe that making an open source, hardware free version of what they're trying to do will prevent Jackoff Vallenti from pushing dollars to kongress to close the PeeCee hole while sucking Bill Gates's balls simultaneously. In the end, the only guarantee you have is that the thing at the end is talking the same language as you and that anyone else can't snoop the traffic and see what's there - so long as your crypto-fu is good, and the security on both machines is decent enough to prevent them from being owned. So why bother? Just because the evil empire is running at full speed towards the precipice doesn't mean we need open source versions of the same insanity that drives'em. ----------------------Kaos-Keraunos-Kybernetos--------------------------- + ^ + :NSA got $20Bill/year|Passwords are like underwear. You don't /|\ \|/ :and didn't stop 9-11|share them, you don't hang them on your/\|/\ <--*-->:Instead of rewarding|monitor, or under your keyboard, you \/|\/ /|\ :their failures, we |don't email them, or put them on a web \|/ + v + :should get refunds! |site, and you must change them very often. --------_sunder_@_sunder_._net_------- http://www.sunder.net ------------ On Wed, 7 Aug 2002, AARG! Anonymous wrote:
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal:
Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications.
In other words, allow a distributed network application to create a "closed world" where it has control over the data and no one can get the application to "cheat". IMO this is clearly the real goal of TCPA and Palladium, in technical terms, when stripped of all the emotional rhetoric.
--------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com
On Wed, 7 Aug 2002, AARG! Anonymous wrote:
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal:
Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications.
Let me restate for clarity, "no one can get access to the data outside the limitations, et al." Simply put, (aside from the usual caveat of "with infinite time and resources") it can't be done in the sense of you and I sharing a document or some such model. Way too many variables/paths/unknowns.
In other words, allow a distributed network application to create a "closed world" where it has control over the data and no one can get the application to "cheat". IMO this is clearly the real goal of TCPA and Palladium, in technical terms, when stripped of all the emotional rhetoric.
"it" I suppose means the "distributed network application". Using the term "no one" makes this whole idea pretty much impossible. "No one" exludes the sufficiently motivated who are willing to go to any lengths. Brute force in its actual sense pretty much always works. Also, when you state that your given scenario is "clearly the real goal" you have already discarded a whopping number of variables, all of which may bear on the challenge. *I* don't know that "this is clearly the real goal of TCPA and Palladium" at all. I accept your opinion as your opinion. I believe you are sincere in interest of discussion. However, it certainly is not my opinion at all. I am not at all clear on what exactly the problem is that TCPA and Palladium are supposed to solve. I presume, until I can be shown otherwise that "it" is a tool to further expand the power of patent and copywrite holders (or more to the point, their barristers) to impose their will on my freedom of speech. Since I don't want to play the part of the fellow who won't be convinced, all I ask is to be shown in clear terms EXACTLY what the problem is, and how EXACTLY this problem is solved by this technology. When I mean exactly, I mean in simple go/no-go logic. I don't need nor particularly want to see the technical specs. There are those out there, and here as well, who are much more qualified to review all that.
Date: Wed, 7 Aug 2002 12:50:29 -0700 From: AARG!Anonymous <remailer@aarg.net>
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal:
Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications.
The model and the goal are a bit different, but how about secure multi-party computation, as introduced by Chaum, Crepeau, and Damgard in 1988 and subsequently refined by others? --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com
Date: Thu, 8 Aug 2002 21:55:40 +0200 From: "R. Hirschfeld" <ray@unipay.nl>
Date: Wed, 7 Aug 2002 12:50:29 -0700 From: AARG!Anonymous <remailer@aarg.net>
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal:
Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications.
The model and the goal are a bit different, but how about secure multi-party computation, as introduced by Chaum, Crepeau, and Damgard in 1988 and subsequently refined by others?
Sorry, I see from an earlier message of yours that you are looking for a simple non-crypto solution, so I guess this doesn't fit the bill. The examples you gave in your earlier message all seem to be equivalent to having the participants send the data to a trusted third party who performs the computation, except that the trusted third party is transplanted to one or more of the participants computers, which are protected against their owners. I guess it boils down to whether or not the level of trust is sufficient. This seems iffy when one of the participants is also the trust provider. --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com
AARG!Anonymous writes:
I'd like the Palladium/TCPA critics to offer an alternative proposal for achieving the following technical goal:
Allow computers separated on the internet to cooperate and share data and computations such that no one can get access to the data outside the limitations and rules imposed by the applications.
Can't be done. I don't have time to go into ALL the reasons. Fortunately for me, any one reason is sufficient. #1: it's all about the economics. You have failed to specify that the cost of breaking into the data has to exceed the value of the data. But even if you did that, you'd have to assume that the data was never worth more than that to *anyone*. As soon as it was worth that, they could break into the data, and data is, after all, just data. Ignore economics at your peril. -- -russ nelson http://russnelson.com | Crynwr sells support for free software | PGPok | businesses persuade 521 Pleasant Valley Rd. | +1 315 268 1925 voice | governments coerce Potsdam, NY 13676-3213 | +1 315 268 9201 FAX |
participants (10)
-
AARG! Anonymous -
Adam Back -
cubic-dog -
John S. Denker -
Matt Crawford -
Mike Rosing -
Pete Chown -
R. Hirschfeld -
Russell Nelson -
Sunder