[Q] Before selling phone, what is the most secure way to wipe / erase information?

Mar 8, 2011
32
0
0
Are there any deep erasing apps out there that can zero the bytes or perform dod style erase methods? I'm trying to erase the internal memory (not the microsd) of the phone. How can I make sure its not recoverable when selling it?

Its just that it contains work related information that I wouldn't want someone trying to recover if they happen to be that type of person.
 

CommanderThor

Senior Member
Jan 22, 2009
115
13
0
Ljubljana
The only way to recover data from phone memory if deleted is with taking phone apart and taking flash memory out(this includes melting down pins). And than put this flash on some other circut board.

Just so that you know how hard is it, enough for most people.

For exstremist what the poster before me said, writing and deleting many times. You could do that on rootet phone with some root explorer program. If you didn use custom ROMs you only need to take care of /data partition, if you did flash a bit DATA partition can move maybe(no sure) so you should do same for /system. Flashing ROM writes to some of system partition, the remainder fill it us with some trash files and to again:)

I heard 20 times is what makes it 100% FBI secure. But 2 times should make it 99.999% secure anyway:)

Edit: That 20 number is for hard drives with same special machines. I am not sure how it is with flash, maybe one rewrite makes it totaly unrecoverable already. If you only worried for softwere recovery once is enough.
 
Last edited:
  • Like
Reactions: beastfromtheeast

lekhwani

Senior Member
Oct 15, 2010
1,876
260
0
I will also give an example. Suppose you have some critical info on your SD card. If you delete that info, you can't rest assured that your critical info has been deleted. Because system just shows it has been deleted. Until something else fills up the same sectors /space on your card, it wont be permanently deleted. But now, if you fill up your whole SD card with, say, videos and songs, then your critical info is really gone. Though simpler solution to do this is to format the SD card.

Same applies for internal memory. You must flash a new rom and fill the data space fully with other apps. Do it without activating/logging in your gmail. Once it's done, you can reflash it with wiping everything from recovery and give/sell to someone as a fresh phone.
 
  • Like
Reactions: beastfromtheeast
Mar 8, 2011
32
0
0
I haven't rooted the phone yet. If I do root just to flash a rom and fill space, will I be able to flash back the original rom and make it so that it was never rooted in the first place?
 

sarfaraz1989

Senior Member
Jan 19, 2011
655
62
0
New Delhi
i wud "dd" all my phone's partition in recovery mode(manually mount them use df in normal mode to know wats mounted) and then flash stock rom using that kdz thing...

PS ..u cud also "dd" your sdcard using
dd if=/dev/random of=/dev/sdb bs=5M count=1000

(/dev/sdb is assumed as your sdcard drive )
5M*1000=5000MB wiped multiply acc to your card's capacity
 
  • Like
Reactions: beastfromtheeast

lekhwani

Senior Member
Oct 15, 2010
1,876
260
0
You r not rooted. In this case:
1.factory reset.
2.install futile apps till your internal memory is full.
3.factory reset again and you are done.
 
Mar 8, 2011
32
0
0
thanks guys, I flashed the stock rom with kdz then installed futile apps via adb until I couldn't install anymore (adb error when phone hit the 20mb mark). One hard reset later, I think its good to go.
 

savagecabage

Member
Aug 20, 2009
39
0
0
shredroid

i have another gmail address that i use for signing up to websites that might start sending me junk. after ive reset the phone i just add that account to the phone and can get access to the market that way without messing up my other main google account settings... then use Shredroid to give the internal memory a good wipin'.

i never tried the other way but using shredroid sounds way quicker that installing apps until youve filled the internal memory, especially if you have a phone with a lot of it
 

srynoname

Member
Sep 20, 2012
43
1
0
ategtre sky

i wud "dd" all my phone's partition in recovery mode(manually mount them use df in normal mode to know wats mounted) and then flash stock rom using that kdz thing...

PS ..u cud also "dd" your sdcard using
dd if=/dev/random of=/dev/sdb bs=5M count=1000

(/dev/sdb is assumed as your sdcard drive )
5M*1000=5000MB wiped multiply acc to your card's capacity
is there actually a dd binary in recovery mode / android at all?