Slashdot Mirror
NSA-resistant Android App 'Burns' Sensitive Messages
angry tapir writes "Phil Zimmermann's Silent Circle, which halted its secure mail service shortly after Lavabit, has released a messaging application for Android devices that encrypts and securely erases messages and files. The application, called Silent Text, lets users specify a time period for which the receiver can view a message before it is erased. It also keeps the keys used to encrypt and decrypt content on the user's device, which protects the company from law enforcement requests for the keys."
Seems similar to pieces of the Guardian Project.
I think this gives a false sense of security. Sure it encrypts messages on my device. And helpfully auto deletes them after the expiry has passed. However, if the person you are worried about gaining access to the messages can silently coerce the transport company (in this case your mobile provider), to release the contents of messages they have stored, of what use it?
Silence is a state of mime.
1. Send order to Google saying, "give us unrestricted read/write access to the persistent storage of all android devices. Oh, and you cannot tell anybody about it."
2. Download the contents of all devices, including the keys.
3. Install keylogger to capture any necessary passwords.
4. Profit!
No, it can't. The recipient could be using a tampered application that ignores the timeout directive. Or it could modify the JVM to lie to the executable about the time or refuse to fire timers. Or modify the JVM to write all the memory transactions to disk (or host) even after the application frees (or GCs) it. Or modify the screen rendering APIs to capture the rendering. Or attach with JDB over ADB and halt the executable while the plaintext is in memory and slurp it out. And, of course, there are apps in the store that will just take a video of the screen.
FWIW, I support the app and I believe the encryption-in-transit is a very worthwhile feature. But the "Burn Notice" is, from a security point of view, useless. If you trust the recipient with the plaintext, you trust the recipient with the plaintext, end of story. Anything else is DRM-esque attempts to put restrictions on a device that you do not own.
TFA makes it sounds like the sender can make decisions about what the receiver's machine does. That is insane (and also impossible, or it's irresponsible to lead users to believe they'll get that). I hope I am misreading the claim.
If the receiver has that control, or if the sender gets to specify advisory info in the hopes that the receiver uses it, ok. If not, then I think one of the most respected programmers ever (PZ) has left the path of wisdom.
"Believe me!" -- Donald Trump
in rare cases NSA wiretaps reveal information about terrorist plots. in most cases of warrantless NSA spying however they do not. the purpose of NSA wiretaps is often used as a guilt generation and conviction assurance mechanism. Yet when it fails to produce any satisfactory outcomes, as this device would preclude it from doing so, the laws can and are frequently adjusted accordingly to suit the prosecutiorial entity. expect the installation or presence of this software to be acceptable grounds for the confiscation of your phone and further investigation of you and your property.
Good people go to bed earlier.
When the hardware, the software, and the transport medium are all compromised it is moronic to continue this "security" game.
It is closed source right? And even if it is not, you need to be able to build the binary from a vetted copy of the source and associated libraries.
We need an organization whose mandate is similar to the NSA. When the FBI, for instance, lawfully obtains evidence that gives them probable cause to get a warrant to invasively follow a chain of evidence, we need this information-gathering capability.
But the NSA over-stepped their bounds, broke the law, and betrayed all Americans and their allies. As a result, people are now more motivated to produce tools to evade organizations like the NSA. Because American citizens have the right to privacy, and they now have to go out of their way to get it, criminals are now gaining more sophisticated tools they can also use to evade the NSA. Looking at the other comments, the app mentioned in particular here isn't necessarily all that effective, but give it time. Pretty soon, you'll be able to put up an impenetrable wall around your data that the NSA can't break through.
The "problem" with this is that there are only two groups who will use these tools. Innocent privacy enthusiasts and criminals. The NSA will be unable to distinguish between them, essentially making rationally paranoid people targets of criminal investigations. And the NSA will be stupid about everyone else, seeing people NOT using encryption as low-hanging fruit, criminalizing countless innocent citizens merely in an effort to show that the NSA is catching *someone*, justifying their enormous budget. (In other words, they will make up criminals to justify their existance.)
If the NSA had obeyed the law, we wouldn't be in this mess, where it is inevitable that we can no longer spy on real criminals, probable cause or not.