----- Forwarded message from Zooko Wilcox-OHearn <zooko@leastauthority.com> ----- Date: Fri, 23 Aug 2013 15:21:47 +0000 From: Zooko Wilcox-OHearn <zooko@leastauthority.com> To: Jon Callas <jon@callas.org> Cc: cryptography@randombit.net Subject: Re: [cryptography] Reply to Zooko (in Markdown) Dear Jon: Thank you for your kind words and your detailed response. I am going to focus only on the issue that I think is most relevant and urgent for your customers and mine. That urgent issue is: what's the difference between the now-canceled Silent Mail product and the products that you are still offering, such as Silent Text? I don't understand why the Lavabit shutdown and the related domestic surveillance disclosures imply that Silent Mail was unsafe in any way that wouldn't also mean Silent Text is unsafe. Before I go on, I'd like to point out a critical fact that some readers might not be aware of: Ladar Levison, the owner of Lavabit, now claims that he is being threatened with jail time *for having shut down the service*: http://investigations.nbcnews.com/_news/2013/08/13/20008036-lavabitcom-owner... This changes the equation, because it means not only can the U.S. federal espionage authorities say "Backdoor all of your customers or close your business.", they can also say "Backdoor all of your customers or go to jail.". As the owner and CEO of a privacy-protecting service (https://LeastAuthority.com) and a U.S. citizen, and as the father of three precious boys who do not want to be separated from me for any length of time, this concerns me greatly. Now, maybe the U.S. espionage authorities wouldn't make that threat again. Maybe Ladar Levison's resistance will teach them that it was a mistake. I don't know, but we have to take into account this possibility for now. Your decision to shutter the Silent Mail product was made because of such possibilities. But your decision to *keep* the Silent Text service (and the others) still operating while shutting down the Silent Mail service would make sense only in the following scenario: Attacker: "We're here to compel you to give us access to the confidential communications of all of your customers." Silent Circle: "But, to do that we would have to change our client — for example, change its random number generator to produce output that we can predict — and then upload a software update to the Apple and Google app stores, and then wait for all of our customers to automatically upgrade to the new version!" Attacker: "Oh, well in that case nevermind." Why do you think that this scenario is plausible? I don't think it is plausible. Instead, I think the conversation would go like this: Silent Circle: "… and then wait for all of our customers to automatically upgrade to the new version!" Attacker: "Okay. Do that." Now, there is a big, complex, and interesting question about how to enable others to *verify* the security of software. It is not impossible, as you suggested. Good progress on enabling independent verification of security is being made, by Whisper Systems (https://whispersystems.org/), my own company LeastAuthority.com, the Tor Project (https://blog.torproject.org/blog/deterministic-builds-part-one-cyberwar-and-...), Gitian (https://gitian.org/), Debian (https://wiki.debian.org/ReproducibleBuilds), and Bitcoin (https://en.bitcoin.it/wiki/Release_process). But before we get into the nuts and bolts of how to facilitate verification of end-to-end security, I want to hammer on the first issue: before going forth to try to improve an issue, we should first admit to our current customers and to the public that the issue exists. We shouldn't mislead our customers into thinking that they are safe from something that they are not. Silent Circle's closure of Silent Mail for the stated reason is inconsistent with its continued operation of the Silent Text service. The stated reason was that the US federal government could compel Silent Circle to backdoor the Silent Mail service. That same reason applies today to the Silent Text service and the other services that Silent Circle is still operating. To be clear, I'm not asking you to shut down your other services. I think that would be a loss for everyone. And I'm not asking you to magically fix all of the problems by tomorrow. I know, in part from your detailed letter, that you are currently working on improving some parts of your process, and I think that there are other techniques that you could use (including licensing your source code as Free and Open Source software) that would help. But I understand the challenges of running a business, actively serving customers, and performing sophisticated engineering all at once. I know that improvement takes time. What I'm asking you to do is to *be clear* with your customers and with the public about the current limitations. Currently, the US federal espionage agencies can compel Silent Circle to secretly provide access to all of Silent Circle's customers' private communications. That's too bad. But it is fixable! But to fix it starts with admitting what the problem is. Regards, Zooko Wilcox-O'Hearn Founder, CEO, and Customer Service Rep https://LeastAuthority.com Freedom matters. _______________________________________________ cryptography mailing list cryptography@randombit.net http://lists.randombit.net/mailman/listinfo/cryptography ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://ativel.com http://postbiota.org AC894EC5: 38A5 5F46 A4FF 59B8 336B 47EE F46E 3489 AC89 4EC5