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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.
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.
There's a button on my Ubuntu PC for creating private/public key pairs and uploading the public key to a ring of public key servers.
Then, people can encrypt emails that only I can read because only I have the private key.
I've always wondered why this isn't better integrated/more automatic when it comes to email systems (gmail?)
Why not just leverage that type of mechanism?
1) Install app
2) it creates a key pair for your phone number
3) It uploads the public key to one of these servers
4) Anybody who texts you using a compatible app, it looks up your private key and encrypts the message only for you.
Job done.
If you can't fit the encrypted message in 120chars, it uploads the encrypted data to a 3rd party and all it sends is a message ID.
Or it uses IP only (like imessage/whatsapp)
Or is uses email as the bulk carrier
All those IP messaging systems must use a 3rd party anyway as you're always NAT'ed behind a real IP address anyway on a mobile connection.
I'm always on a 10.x.x.x address.
If only there were some sort of secure way of exchanging keys over an insecure medium...
If only there were some sort of secure way of exchanging keys over an insecure medium...
Saaay, someone should tell Phil Zimmerman about that - I'll bet he could really put it to some good use!
Saaay, someone should tell Phil Zimmerman about that - I'll bet he could really put it to some good use!
I can imagine that the result would be some pretty good privacy for the ordinary user.
Ezekiel 23:20