Wednesday, February 6, 2013
pressure for the Silent Circle team to release its application source code. While some of the deployed protocols are in the public domain, the source code for particular applications have not been released yet making it difficult for security researchers to render an informed opinion on its implementation.
In the security community, this is vitally important because publicly-available "open" source code with compilation instructions also allows for independent compiling of the code, reproducible steps to get an executable, and verification of hashes against the code that is being downloaded from the App Store. Of course, not everyone will perform this independent verification for every download but that isn't really necessary. As long as there is a reasonable level of awareness regarding the product, any deviation from original trusted source code will be noticed rapidly.
Set to be approved by Apple on February 8th, the new encrypted data transfer app enables peer-to-peer encryption of any digital data -- text, images, audio, video, and even zipped data files -- all from a tablet or smartphone with a built-in burn feature. The release of the Silent Text Android version will follow next.
This is revolutionary technology because of the consolidated approach to functionality across platforms but even more so because of its user-friendly implementation. Security and cryptography products can only be great if they are used and Silent Circle has gone to great lengths to ensure that the process is as transparent and hassle-free as possible.
Chief Technical Officer Jon Callas says that, with their new S-Cloud Broker technology based on modified convergent encryption, Silent Circle side-steps a lot of traditional objections that people have to cloud systems, such as "the security and privacy of their valuable data." It permits Silent Circle to run their business while minimizing the risk to their end customers and, according to Callas, "this means that there are fewer objections to anyone who wants the advantages of a cloud service, but has business and regulatory concerns about their service provider."
The encryption keys do not pass through the central servers and all cryptographic operations are performed on the client side. This is something that Cryptocat developer Nadim Kobeissi knows about intimately. His open-source encrypted peer-to-peer chat product went through rigorous challenges in the security community ultimately resulting in safer design choices.
Kobeissi's current challenge for Silent Circle to release the full source code with proper documentation is emblematic of the community's attitude towards new security and encryption products in general. Consequently, many in the computer security field are reserving judgement about Silent Circle until the conditions in Kobeissi's challenge can be met.
Despite the fact that Silent Circle submits their code for several third-party audits, releasing an app like this one prior to source code release is bound to raise some questions. The source code for the existing Silent Text version is here and the company tells me that the new Silent Text source code will be released sometime in March or April after confirming legal issues such as licenses for third-party libraries.
If ever forced to comply with a U.S. law enforcement request, CEO Mike Janke implies that Silent Circle can move to a jurisdiction that won’t try to force them to participate in surveillance operations. However, the legal jurisdiction may not matter because if the source code is released and readily verifiable, the malicious participation of Silent Circle to surveil and host "bad" code for download would be effectively neutered. Short of crippling Apple's iOS and Google's Android, surveillance operations then would proceed to obtaining the keys in another fashion such as direct keylogging or contempt of court charges relating to key disclosure.
Speaking at the Kaspersky Lab Security Analyst Summit in Puerto Rico yesterday, President and Co-Founder Phil Zimmermann emphasized that Silent Circle will never include law-enforcement access mechanisms for its products.
"We really, really don't have the keys. This is for serious people in serious situations. I think probably it's not a good idea to trust crypto software if they don't publish the source code. It's not just [to look for] back doors, but what if they screw up and make a mistake?
We're not going to build in any back doors in our service. I've spent my whole career on the principle of no back doors, so I'm not going to start now. One thing we won't do is cave in."For the moment, that's a lot more reassuring than the closed-source, proprietary free app from Wickr that doesn't even intend to release its application source code.