Pervasive Monitoring as Network Attack
New IETF RFC: “RFC 7258: Pervasive Monitoring Is an Attack” that designers must mitigate.
Slashdot thread.
EDITED TO ADD (6/7): Hacker News thread.
Entries Tagged "IETF"
Page 1 of 1
NSA Spying: Whom Do You Believe?
On Friday, Reuters reported that RSA entered into a secret contract to make DUAL_EC_PRNG the default random number generator in the BSAFE toolkit. DUA_EC_PRNG is now known to have been backdoored by the NSA.
Yesterday, RSA denied it:
Recent press coverage has asserted that RSA entered into a “secret contract” with the NSA to incorporate a known flawed random number generator into its BSAFE encryption libraries. We categorically deny this allegation.
[…]
We made the decision to use Dual EC DRBG as the default in BSAFE toolkits in 2004, in the context of an industry-wide effort to develop newer, stronger methods of encryption. At that time, the NSA had a trusted role in the community-wide effort to strengthen, not weaken, encryption.
We know from both Mark Klein and Edward Snowden—and pretty much everything else about the NSA—that the NSA directly taps the trunk lines of AT&T (and pretty much every other telcom carrier). On Friday, AT&T denied that:
In its statement, AT&T sought to push back against the notion that it provides the government with such access. “We do not allow any government agency to connect directly to our network to gather, review or retrieve our customers’ information,” said Watts.
I’ve written before about how the NSA has corroded our trust in the Internet and communications technologies. The debates over these companies’ statements, and about exactly how they are using and abusing individual words to lie while claiming they are not lying, is a manifestation of that.
Me again:
This sort of thing can destroy our country. Trust is essential in our society. And if we can’t trust either our government or the corporations that have intimate access into so much of our lives, society suffers. Study after study demonstrates the value of living in a high-trust society and the costs of living in a low-trust one.
Rebuilding trust is not easy, as anyone who has betrayed or been betrayed by a friend or lover knows, but the path involves transparency, oversight and accountability. Transparency first involves coming clean. Not a little bit at a time, not only when you have to, but complete disclosure about everything. Then it involves continuing disclosure. No more secret rulings by secret courts about secret laws. No more secret programs whose costs and benefits remain hidden.
Oversight involves meaningful constraints on the NSA, the FBI and others. This will be a combination of things: a court system that acts as a third-party advocate for the rule of law rather than a rubber-stamp organization, a legislature that understands what these organizations are doing and regularly debates requests for increased power, and vibrant public-sector watchdog groups that analyze and debate the government’s actions.
Accountability means that those who break the law, lie to Congress or deceive the American people are held accountable. The NSA has gone rogue, and while it’s probably not possible to prosecute people for what they did under the enormous veil of secrecy it currently enjoys, we need to make it clear that this behavior will not be tolerated in the future. Accountability also means voting, which means voters need to know what our leaders are doing in our name.
This is the only way we can restore trust. A market economy doesn’t work unless consumers can make intelligent buying decisions based on accurate product information. That’s why we have agencies like the FDA, truth-in-packaging laws and prohibitions against false advertising.
We no longer know whom to trust. This is the greatest damage the NSA has done to the Internet, and will be the hardest to fix.
EDITED TO ADD (12/23): The requested removal of an NSA employee from an IETF group co-chairmanship is another manifestation of this mistrust.
Take Back the Internet
Government and industry have betrayed the Internet, and us.
By subverting the Internet at every level to make it a vast, multi-layered and robust surveillance platform, the NSA has undermined a fundamental social contract. The companies that build and manage our Internet infrastructure, the companies that create and sell us our hardware and software, or the companies that host our data: we can no longer trust them to be ethical Internet stewards.
This is not the Internet the world needs, or the Internet its creators envisioned. We need to take it back.
And by we, I mean the engineering community.
Yes, this is primarily a political problem, a policy matter that requires political intervention.
But this is also an engineering problem, and there are several things engineers can—and should—do.
One, we should expose. If you do not have a security clearance, and if you have not received a National Security Letter, you are not bound by a federal confidentially requirements or a gag order. If you have been contacted by the NSA to subvert a product or protocol, you need to come forward with your story. Your employer obligations don’t cover illegal or unethical activity. If you work with classified data and are truly brave, expose what you know. We need whistleblowers.
We need to know how exactly how the NSA and other agencies are subverting routers, switches, the Internet backbone, encryption technologies and cloud systems. I already have five stories from people like you, and I’ve just started collecting. I want 50. There’s safety in numbers, and this form of civil disobedience is the moral thing to do.
Two, we can design. We need to figure out how to re-engineer the Internet to prevent this kind of wholesale spying. We need new techniques to prevent communications intermediaries from leaking private information.
We can make surveillance expensive again. In particular, we need open protocols, open implementations, open systems—these will be harder for the NSA to subvert.
The Internet Engineering Task Force, the group that defines the standards that make the internet run, has a meeting planned for early November in Vancouver. This group needs to dedicate its next meeting to this task. This is an emergency, and demands an emergency response.
Three, we can influence governance. I have resisted saying this up to now, and I am saddened to say it, but the US has proved to be an unethical steward of the Internet. The UK is no better. The NSA’s actions are legitimizing the internet abuses by China, Russia, Iran and others. We need to figure out new means of internet governance, ones that makes it harder for powerful tech countries to monitor everything. For example, we need to demand transparency, oversight, and accountability from our governments and corporations.
Unfortunately, this is going play directly into the hands of totalitarian governments that want to control their country’s Internet for even more extreme forms of surveillance. We need to figure out how to prevent that, too. We need to avoid the mistakes of the International Telecommunications Union, which has become a forum to legitimize bad government behavior, and create truly international governance that can’t be dominated or abused by any one country.
Generations from now, when people look back on these early decades of the Internet, I hope they will not be disappointed in us. We can ensure that they don’t only if each of us makes this a priority, and engages in the debate. We have a moral duty to do this, and we have no time to lose.
Dismantling the surveillance state won’t be easy. Has any country that engaged in mass surveillance of its own citizens voluntarily given up that capability? Has any mass surveillance country avoided becoming totalitarian? Whatever happens, we’re going to be breaking new ground.
Again, the politics of this is a bigger task than the engineering, but the engineering is critical. We need to demand that real technologists be involved in any key government decision making on these issues. We’ve had enough of lawyers and politicians not fully understanding technology; we need technologists at the table when we build tech policy.
To the engineers, I say this: we built the Internet, and some of us have helped to subvert it. Now, those of us who love liberty have to fix it.
This essay previously appeared in the Guardian.
EDITED TO ADD: Slashdot thread. An opposing view to my call to action. And I agree with this, even though the author presents this as an opposing view to mine.
EDITED TO ADD: This essay has been translated into German.
NIST Hash Workshop Liveblogging (2)
In the morning we had a series of interesting papers: “Strengthening Digital Signatures via Randomized Hashing,” by Halevi and Krawczyk; “Herding Hash Functions and the Nostradamus Attack,” by Kelsey and Kohno; and “Collision-Resistant usage of MD5 and SHA-1 via Message Preprocessing,” by Szydlo and Yin. The first and third papers are suggestions for modifying SHA-1 to make it more secure. The second paper discusses some fascinating and cool, but still theoretical, attacks on hash functions.
The last session before lunch was a panel discussion: “SHA-1: Practical Security Implications of Continued Use.” The panel stressed that these are collision attacks and not pre-image attacks, and that many protocols simply don’t care. Collision attacks are important for digital signatures, but less so for other uses of hash functions. On the other hand, this difference is only understood by cryptographers; there are issues if the public believes that SHA-1 is “broken.”
Niels Ferguson pointed out that the big problem is MD5, which is still used everywhere. (Hell, DES is still everywhere.) It takes much longer to upgrade algorithms on the Internet than most people believe; Steve Bellovin says it takes about one year to get the change through the IETF, and another five to seven years to get it depoloyed. And that’s after we all figure out which algorithm they should use.
Georg Illies gave a perspective from Germany, where there is a digital-signature law in effect. In addition to the technology, there are legal considerations that make it harder to switch.
The panel seemed to agree that it’s still safe to use SHA-1 today, but that we need to start migrating to something better. It’s way easier to change algorithms when you’re not in the middle of a panic.
There was more talk about algorithm agility. This problem is larger than SHA. Our Internet protocols simply don’t have a secure methodology for migrating from one cryptographic algorithm to another.
Bottom line: Don’t use SHA-1 for anything new, and start moving away from it as soon as possible. To SHA-256, probably.
And now it’s lunchtime.
Sidebar photo of Bruce Schneier by Joe MacInnis.