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Will your mobile squeal to the police?

Odin Eidskrem

Confused.. and might be wrong.. 

--

Flash memory, of the type used in most smartphones, is not normally erased as such. Deleted data is marked as deleted, then overwritten when the space is needed - but there is a limit to how often Flash can be written, so the OS will avoid overwriting things for as long as possible (a process called wear-levelling) to ensure the whole memory is used.

For example: an iPhone may have 16GB of memory, but most users will only fill half that, and once full the data generally remains pretty static. So old information can hang around for years, and be extracted using the right forensic tools.

--

Wouldn't it be the other way around? Wouldn't the wear leveling algorithm always try to save information in the place that had been used the least so as to 'wear out' the flash memory evenly?

Anonymous Coward

Bill 

"In the UK it's also standard practice to scoop up mobiles belonging to the recently deceased, to see what they were doing prior to being dead."

Care to expand this sentence a bit?

Neil Sparky93

scoop up 

Pirate

"In the UK it's also standard practice to scoop up mobiles belonging to the recently deceased, to see what they were doing prior to being dead."

this is just to check no one was trying to kill, or self harm etc.

Remy Redert

@Confused 

Using the least often used bit of memory means that all memory will be used sequentially. Start at the 'top' and work your way down. When something is marked 'deleted', you can mark that as availble space so that when you reach the bottom and start working from the top again, you can use that space for something else.

Jim Cosser

Re: Confused 

Odin,

I think thats what the article is saying, the the area used least is generally blank space especially on something as large as the iPhone.

If it constantly puts it in blank space then the deleted files are rarely overwritten until the whole 16GB is used.

Anonymous Coward

Re: Confused... 

Thumb Up

No, you've got it right, that is how (one of the techniques used by) wear leveling works.

But I don't see how that disagrees with the text you quoted, so maybe I'm misreading something (or I've gotten confused myself - not an entirely unusual event).

Anonymous Coward

Works both ways 

Black Helicopters

Build your own digital alibi.....

Guy

Prior to being dead? 

Joke

Living I would assume! If the police need to check someones mobile to find this out, we really are at the bottom of the slippery slope....and digging

Mark Webster

@Odin Eidskrem 

"Wouldn't the wear leveling algorithm always try to save information in the place that had been used the least"

Yes, that's exactly what the author is saying :)

"Wearing out" is as much of a problem with current generation flash memory as it was before, but wear-levelling algorithms are still used ubiquitously.

Jamie Kitson

arf arf 

Paris Hilton

If he was "signing on" he wasn't illiterate at all!

Glenn Gilbert

Give it to DHL? 

Happy

Give the phone to DHL with specific routing instructions. Then let "them" pick the bones out of that!

Anonymous Coward

Which is probably why 

Which is probably why the payphones near our city train station are busy most evenings, occupied by blingy geezers in expensive trainers and dodgy shades. They may be evil but they arent stupid.

Andres Gabriel Villalobos

Today's criminals aren't generally that stupid... 

Pirate

Your remark : "Today's criminals aren't generally that stupid" reminds me of the computers recovered by the Colombian goverment in a attack to the FARC terrorists....

Those computers shown a web of links between the venezuelan and ecuadorian goverment and the FARC guerrillas....

Today´s criminals ARE that stupid!!!

Dave Bell

I now feel horribly old. 

20 years ago?

Psion Organiser?

Aargh!

Anonymous Coward

one more reason 

Black Helicopters

I don't want a mobe...

James

Continuing 

"there is a limit to how often Flash can be written, so the OS will avoid overwriting things for as long as possible"

Wouldn't the wear leveling algorithm always try to save information in the place that had been used the least?

---

Exactly. Which area has been used the least number of times: one with existing data that needs to be 'overwritten' (written >= 1nce) or one without (i.e. blank, written == 0)?

PC Paul

Mobes of the Dead 

I believe a common use the Police have for newly chattelised mobiles is to check whether the deceased was driving while texting/chatting/screaming or whatever they last did on it...

Anonymous Coward

forget the pistol, dig up that phone 

One more item to dredge the river for.

Forget the pistol, find that phone.

Anonymous Coward

OpenMoko is going to be big 

Simplest way to ensure you have a secured handset.

Oldfogey

@ I now feel horribly old. 

Why? The various Psion models remain some of the best PDA's ever produced. I use mine (3a) all the time as a really easy datastore that runs for months on a couple of AA batteries.

And no flash memory.

I have yet to see a new device, even at 20x what I paid for the Psion, that actually offers any additional functionality that I need.

Same with my phone - a Philips Savvy. It makes phone calls.

Iain

So, the police check your phone... 

Black Helicopters

...post mortem. If I die suddenly, and, lets face it, shit does happen, I would not really fancy the police poking through my electronic equipment. I wonder if you can be prosecuted posthumously under the new Criminal Justice Bill...

Whatever, I wouldn't fancy my grieving relatives (I hope they would be grieving anyway...) being old by the police 'Oh by the way your son/brother/husband/nephew/uncle is a massive pevert' (according the the government).

Apart from that aspect, I have various bank details and accounts stored on my laptop. Lets think how that would go:

I die.

Police take laptop to check wasn't topped by irate forum moderator.

Police forensically delve into files, unencrypt bank details.

Police lose laptop.

Criminal finds laptop, rinses my accounts...

Anonymous Coward

@oldfogey 

Thumb Down

I used to have a Philips Savvy. Bloody awful lump of a thing.

Couldn't even add your own ring tones...

heystoopid

So for the paranoid 

Black Helicopters

So for the paranoid , what is needed is either a high temperature furnace temperature > 1500 degrees Celsius kiln to completely destroy the phone , a microwave oven to nuke the sim cards on a regular basis and a cloner to create duplicate backups since the sims are fairly cheap and readily available so one can nuke it on a weekly basis or the old write zeroes to the empty data spaces delete trojan worm phone software in the interim and throw the old one into the high temperature furnace to ensure absolute destruction !

As for the Columbian Army versus FARC it is an area in the world where propaganda rules absolutely on the US side of the fence where torture on all captive victims is the rule rather then the exception and so thus all claims from any US backed government agency would have to be viewed using Occams Razor absolutely for what they claim and that which is reality are at opposite ends of the universe , given the current classic example of a shattered blighted country called Iraq !

But then again , one used to hear much about the same thing back in Chairman Ronnie's time in a country called Nicaragua about how Daniel Ortega's Mob were losing the fight for their own country ! But soon the uneducated peons kicked those evil merkin gringo supported drug lords called the Somoza family butt all the way back across the international border plus a few extra miles for a good measure even back then as in the jungles have no visible border posts !

Anonymous Coward

"if you're stopped and searched they're only allowed to check for weapons" 

Black Helicopters

Really? So they can't search for alcohol, drugs, the odd bomb strapped around the waist? Oh wait that last one is a weapon.

Oldfogey

@ Philips Savvy. 

So you can't put a ringtone on it.

It rings. I answer. What more do I want?

And I always know it's mine, because everybody else has this weeks version of Crazy Frog, and when a phone rings, 10 people pull theirs out.

A phone is for making phone calls. The rest is just posing.

Mr ChriZ

@Philips Savvy 

Thumb Up

I Had a Savvy too.

Loved it although the battery life was awful, and the aerial always ended up poking you when you had it in your pocket.

However so worth it for the, da da da da da (Puppy Power) noise everytime you got a text message, and also the funky Horrorscope tool!

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