How to cancel all data memory (photos, audio, videos, and files) from a phone or a PC, with a signal or EMP through a remote or a specific device?

Question

I need to wipe out all data from a multiple phone or PC devices, in a range of 1-6 meters. The best option should be with a signal from a device, like a remote or something, that sends a frequency or an EMP that eliminates all the data in the phone (memory card included) or PC, leaving no trace of the cause of the data cancellation.

Answer 1

Won't work, especially not without a trace.

Those phones will have different operating systems, from current Android versions over various outdated Android versions to iOS. Perhaps even a Windows phone. An exploit would have to work against all of them.

That leaves brute electromagnetic force, which will leave a trace. Or brute kinetic force.

Or you could assume, for your setting, that there are NSA backdoors in all those operating systems, and that the bad guys have access to them. But using such a backdoor could make people look for it, and find it, so an agency would not use it lightly.

Answer 2

Cannot be done directly.

"eliminates all the data in the phone (memory card included) or PC" -- you are talking of probably up to three different memory storage technologies, and two of them are not even sensitive to EMPs, requiring extreme electrical discharges instead. Or lots of heat.

The kind of electrical charge buildup, or magnetic flux variation, that would fry a NAND memory would leave plenty of traces.

With preparation, you can do this indirectly.

The phones, PC etc. are powered and primed with a tailored trojan program (you'll need a version of the trojan for each platform and operating system). Upon receiving the signal - possibly even an audio signal (1) - the trojan activates, wipes everything, cleans up after itself and self-deletes. The wipe can be as thorough as you want, from specific data disappearing to the whole system becoming unusable.

It is also possible to corrupt file systems in very specific ways so as to both trick the operating system into malfunctioning, and a not too thorough repairman into believing there has been a hardware failure. Of course, such a failure in several devices all at once would be suspicious in the extreme.

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(1) on most systems you can even use ultrasound with a good chance the microphone will pick it up even if it is not designed to do so - you'll need a complex signal to work around distortion, disturbances, background noise and hardware limitations, but we have error-correction integrity codes that can allow a recognizable signal to come in from a probe in deep space so it's doable.

Answer 3

You can't--there's nothing to distinguish data memory from system memory. Even if you could somehow wipe the memory (quite questionable) you would brick the phone, not just erase it.