Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?

Comment Re:Answer me this... apk (Score 5, Informative) 44 44

The answer is that it varies - GPUs are anywhere from mediocre to useless at "normal" crypto.

It depends on whether the particular encryption algorithm/mode in use is parallelizable or not. For example, CBC is not parallelizable - you have to encrypt each block of data serially. GPUs are useless at CBC mode encryption. More modern modes like GCM and XTS are parallelizable to an extent, as you can encrypt multiple blocks at once, but there is still a serial dependency in the process (there is no real way of completely getting rid of all dependencies while keeping the algorithm usefully secure), so you still need to do some pre or post-processing of the data in a serial fashion. And even then, you're limited by bandwidth in/out of the GPU.

Public-key crypto (RSA, DSA, and ECDSA) isn't really parallelizable either as it only deals with small data sizes. And typical hash algorithms like SHA-1 and SHA-256 are also not parallelizable in their construction.

Thing is, CPUs these days have hardware AES encryption acceleration, making this mostly a moot point. GPUs are good at doing the same thing many times in parallel, which is what breaking encryption requires, but not regular usage.

Comment Motofone F3 (Score 1) 313 313

The Motofone F3 is dirt cheap, light, compact and lasts long on a charge. It features an epaper display that is perfectly readable in full sunlight and is always on. It's quite convenient to be able to read the time without pressing the power button first. The disadvantage is that the segment display shows only a few letters at a time. If you want to do any amount of texting, it's too inconvenient.

Comment Apps crashing (Score 1) 484 484

I do have some apps crash, but that's the app developer's problem. Not much the OS vendor can do about that.

I've written a somewhat popular Android app and most of its crashes are either the fault of the runtime or of vendor specific customizations.

The Developer Console provides excellent reporting on both uncaught Java exceptions and crashes in native code. Most often, the Dalvik VM crashes during garbage collection. The Dalvik class loader is also flaky and has issues with multithreading that only got worked around in newer versions. I've also seen the libchromium crash inside my app from adverts delivered by Googles Admob service, which is somewhat scary from a security perspective.

Another issue is that apps using Googles compatibility library now crash on HTC devices running Android 4.1 as soon as the user presses the menu key. HTC is no longer providing updates and Google simply states that it's not their fault and therefore not their problem. Now thousands of app developers have to independently find out about the issue and work around it.

So when an app crashes, there's a good chance that it's not the fault of the app developer. On a brighter note, the ART VM used in Android 5 and newer seem to be rock solid.

Comment Re:capabilities? (Score 2) 83 83

AFAIK, Stingray is based on an IMSI catcher. It simulates a cell tower and gets cell phones in the area to connect to it by providing the strongest signal. It then records the data of all connected cell phones and forwards it to the network.

Since IMSI catchers are well understood, all this secrecy is a bit surprising. It makes speculation about additional capabilities plausible. It could use exploits in the modem software to install malware. Such malware could do all sorts of things like reading local files, including contacts, messages, browsing history and possibly passwords. It could also store files on the device. It could provide side channels for encrypted communication from https to WhatsApp calls. It could also turn on the microphone and camera. All this is pure speculation, but it seems plausible.

Comment Re:Don't forget Firefox Hello! (Score 1) 147 147

Videoconferencing from any device on the planet without installing any special software is bloat?

YES, in the same way that every user on the planet would probably want a calculator once in a while but that doesn't mean the browser needs to add one!

Firefox comes with a couple of calculators built in. It has since before it was called Firefox.

Comment Re:Maybe not the power supply? (Score 1) 192 192

Usually, "epoxy" around the edges of a BGA chip is neither an anti-hacking attempt nor a light-proofing attempt. It's called underfill, and its chief purpose is to increase mechanical strength and make the bond more durable than tiny bare solder balls would be on their own.

Some people manage by the book, even though they don't know who wrote the book or even what book.