how are SSD hard drives in terms of security

I don't know if anyone has asked this question yet but I was wondering how are SSD hard drives in terms of security and file recovery? For example, if I save sensitive data on a SSD and deleted/secure wiped them off what are the chances that data can be recovered by another party?

Good question, I would think it would be the same as a regular drive though from looking at the way they work.

The same recovery programs could be run - so software recovery is possible.

But physical recovery would be highly unlikely. HDD platters and bearings etc may be rebuilt in sterile labs, but a cracked microchip is a good start for a DIY keyring

if physical recovery is not possible what would it take to make software recovery not possible either? extra wipes until there is no trace left?

thegreek said:

if physical recovery is not possible what would it take to make software recovery not possible either? extra wipes until there is no trace left?

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When you erase something off of your disk, it doesn't actually erase it.

It just forgets where it is....basically.

thideras said:

When you erase something off of your disk, it doesn't actually erase it.

It just forgets where it is....basically.

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That's solved by a simple format, but isn't the concern of secure erasure with regards to physical storage media.

The problem on hard drives is that magnetic fields aren't digital, they're analog.
Let's say we want to change a 1 to a 0. You apply an opposite field, and it really becomes 0.4. It's less than 0.5, so it LOOKS like a 0. If you write 0 again, it becomes 0.2.
So let's say you erase a file by writing zeroes to the data once over. Someone could still see the small differences and recover the file.

This example is overly simplified.

I don't know for sure, but I think SSD drives have the same level of security as magnetic hard drives. People can recover data off your computer RAM, which is much more volatile, so pulling data from something that you hardly change seems easier.

dogbert_2001 said:

I don't know for sure, but I think SSD drives have the same level of security as magnetic hard drives. People can recover data off your computer RAM, which is much more volatile, so pulling data from something that you hardly change seems easier.

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Uh...RAM looses everything when power is lost. I have never heard of a way to read what was on the RAM...if you have a link, I would be happy to read it though. Working tech support isn't as exciting as it sounds

dogbert! long time no speak

i suppose we need to find out exactly what "switches" inside an SSD to make it a 0 or a 1. Then we could get into thinking how it could be recovery read.

thideras said:

Uh...RAM looses everything when power is lost. I have never heard of a way to read what was on the RAM...if you have a link, I would be happy to read it though. Working tech support isn't as exciting as it sounds

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I too would like to read a link for the statement on recoverable data from RAM.

I wonder if the move towards SSD will be slow, just on the frailty of the data; I bet major HD manufactures pay attention more to companies like google and yahoo, who need data integrity, rather than silly nerds like us.

But then again a swappable RAID array would cover data safety, and I bet google and its football field sized data centers would love the cut in electrical costs from cooler running SSD's.

I cannot wait for zero load times, and waiting for the mouse response rather than HD activity.

dogbert_2001 said:

http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html

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AWESOME!!!

I have reading material for today!!! Thanks!

dogbert_2001 said:

http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html

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Brilliant, thanks!

dogbert_2001 said:

That's solved by a simple format, but isn't the concern of secure erasure with regards to physical storage media.

The problem on hard drives is that magnetic fields aren't digital, they're analog.
Let's say we want to change a 1 to a 0. You apply an opposite field, and it really becomes 0.4. It's less than 0.5, so it LOOKS like a 0. If you write 0 again, it becomes 0.2.
So let's say you erase a file by writing zeroes to the data once over. Someone could still see the small differences and recover the file.

This example is overly simplified.

I don't know for sure, but I think SSD drives have the same level of security as magnetic hard drives. People can recover data off your computer RAM, which is much more volatile, so pulling data from something that you hardly change seems easier.

Click to expand...

Very cool. You are exactly right about the RAM.

that thing someone linked said:

Contrary to conventional wisdom, "volatile" semiconductor memory does not entirely lose its contents when power is removed. Both static (SRAM) and dynamic (DRAM) memory retains some information on the data stored in it while power was still applied. SRAM is particularly susceptible to this problem, as storing the same data in it over a long period of time has the effect of altering the preferred power-up state to the state which was stored when power was removed. Older SRAM chips could often "remember" the previously held state for several days. In fact, it is possible to manufacture SRAM's which always have a certain state on power-up, but which can be overwritten later on - a kind of "writeable ROM".

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Hipcrostino said:

i suppose we need to find out exactly what "switches" inside an SSD to make it a 0 or a 1. Then we could get into thinking how it could be recovery read.

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Exactly.

I've yet to find a reliable source stating exactly *WHAT* technology the Mtron SSDs use. Being "solid state", we know the memory is stored on chips. The storage is non-volatile, so I can only assume it uses flash memory. The big question is does it use NAND or NOR memory?

Why would it use NAND?

• The most prominent form of flash memory today
• Much easier to make in the high densities you need to cram in 64GB

Why would it use NOR?

• NOR chips can withstand fewer erasures than NAND. The 140 year @ 50GB/day reliability figure given by Mtron nicely fits with the expected erasure count for NOR.
• Theoreticaly capable of a higher speed (though it has a smaller advantage against multi-level cells) since memory is accessed in parallel rather than serial.

If Mtron drives make use of NAND memory, then data recovery is the same as for other NAND-based drives (e.g., USB sticks). NAND memory controllers almost always perform wear-levelling to reduce how often any single page is written to. Rather than overwriting a page of memory, the controller will write to an unused portion of memory, and then have the page address map to the new physical address. Since the original data was never actually overwritten, you can still retrieve the contents if you just bypass the controller

If Mtron drives make use of NOR memory, it's still possible that a wear-leveling controller sits between you and the memory, but its not guarnteed.

In either case, if the data is actually overwritten, then you'll need to look at the physical method of writing data for the appropriate technology to determine how recovery would occur. Wikipedia says that NAND typically uses Fowler-Nordheim tunneling for erasing/writing, while NOR uses quantum tunneling and hot electron injection for erasure and writing respectively.

JigPu