Pioneer In Internet Anonymity Hands FBI A Huge Gift In Building Dangerous Backdoored Encryption System
from the not-a-good-idea dept
Few doubt Chaum's cryptography skills or pedigree. He was instrumental in the early days of computer cryptography and what anonymity we have online today owes a lot to Chaum. But his latest plan is... troubling:
At the Real World Crypto conference at Stanford University today, Chaum plans to present for the first time a new encryption scheme he calls PrivaTegrity. Like other tools Chaum has spent his long career developing, PrivaTegrity is designed to allow fully secret, anonymous communications that no eavesdropper can crack, whether a hacker or an intelligence agency.That part sounds good, right? But then there's this:
That ambitious privacy toolset aside, Chaum is also building into PrivaTegrity another feature that’s sure to be far more controversial: a carefully controlled backdoor that allows anyone doing something “generally recognized as evil” to have their anonymity and privacy stripped altogether.Unfortunately, Chaum is both totally missing the point and playing right into the FBI's hands. The argument of basically every other cryptographer is that building any encryption system is incredibly difficult -- and introducing any sort of backdoor opens up massive and dangerous vulnerabilities -- whether the original creators recognize it or not. The second you introduce a backdoor -- even using Chaum's weird "nine people in nine countries" system -- you have introduced a vulnerability. A vulnerability that can and will be abused by others. You are introducing a security flaw. And that's a massive security problem.
Whoever controls that backdoor within PrivaTegrity would have the power to decide who counts as “evil”—too much power, Chaum recognizes, for any single company or government. So he’s given the task to a sort of council system. When PrivaTegrity’s setup is complete, nine server administrators in nine different countries would all need to cooperate to trace criminals within the network and decrypt their communications. The result, Chaum argues, is a new approach that “breaks the crypto wars,” satisfying both the law enforcement agencies who argue that encryption offers a haven for criminals, and also those who argue that it’s necessary to hobble mass spying.
Chaum's bragging about this system totally misses this point:
“If you want a way to solve this apparent logjam, here it is,” says Chaum. “We don’t have to give up on privacy. We don’t have to allow terrorists and drug dealers to use it. We can have a civil society electronically without the possibility of covert mass surveillance.”That assumes that his system can't be hacked. That's a dangerous claim. Yes, the "key" is split into 9 pieces, but it's still introducing a vulnerability and undermining the integrity of the system.
And, worst of all, as ACLU security expert Chris Soghoian points out, this is little more than a huge political gift to the FBI, who can go back to their stupid claims that if technologists just work harder they can come up with a "solution" to the false problem of "going dark." Similarly, you have politicians like Hillary Clinton insisting that if only techies come together with government they can "solve" the encryption/"going dark" issue.
And now you can bet, without a doubt, that law enforcement and clueless politicians will start pointing to Chaum's offering as an example of a "solution."
Security experts: Backdoors weaken security. They're a bad idea. Chaum: I've built a new system with a backdoor. FBI: See? It is possible.— Christopher Soghoian (@csoghoian) January 6, 2016
And, of course, none of PrivaTegrity's security claims have been checked or audited publicly at this point. Chaum admits that while the eventual plan will involve routing messages (multiple times) though nine servers in nine different countries, the prototype runs entirely on Amazon's cloud computing infrastructure. Either way, at the very least, the system makes it clear that decrypting all such traffic requires attacking and compromising just nine servers. If you don't think the NSA can do that, you haven't been paying attention.