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Comment on iPhone owners say the latest iOS update is resurfacing deleted nudes

The reason that TRIM enhances life by facilitating wear leveling is that it lets the firmware know that the block no longer has useful data

Ah I see the disconnect, TRIM doesn’t live in the OS outside of the firmware, TRIM is part of the controller firmware and is exposed as an ATA command for the OS to utilize

The study I have linked in my original comment goes more in-depth

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tal@lemmy.today ⁨5⁩ ⁨months⁩ ago

Ah I see the disconnect, TRIM doesn’t live in the OS outside of the firmware, TRIM is part of the controller firmware and is exposed as an ATA command for the OS to utilize

Yes, I know.

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- cm0002@lemmy.world ⁨5⁩ ⁨months⁩ ago
  Direct PDF link
  
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  - tal@lemmy.today ⁨5⁩ ⁨months⁩ ago
    I mean, I read the PDF, the problem was the viewer bogging down.
    
    googles
    
    This sounds like what I expected:
    
    superuser.com/…/triming-as-alternative-to-securel…
    
    If data security is your concern, it should be noted that neither a SECURE_ERASE nor a TRIM actually erase the flash cells. The SSD firmware keeps a list of which cells are allocated and which are not. A TRIM simply marks a cell as unallocated the same way deleting a file causes the filesystem to mark a cluster as unallocated. No attempt is made to actually erase the data. A read request from an unallocated cell simply causes the device to return 0x00 (or some other bit pattern) without actually checking the cell’s contents.
    
    There is no effective way of securely wiping an SSD. Forensics tools that can interface with the firmware directly can see the cells’ contents. Also, there is more storage on the device than what is accessible from user-space. These extra cells are used in garbage collection. Garbage collection can reallocate cells on-the-fly and can still work even on a drive that is 100% full. A SECURE_ERASE may (probably does) TRIM those cells, but a blkdiscard or fstrim certainly wouldn’t, since they use sector numbers to identify the areas to be TRIMmed.
    
    The only way to securely erase an SSD is to destroy it. This is the policy of most companies in health care, banking, and government when surplussing equipment.
    
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    barsquid@lemmy.world ⁨5⁩ ⁨months⁩ ago
    This is a complete digression but do you know if there is a consumer hardware that can be reliably erased? I’m trying to make something behave as an affordable HSM. If I could store a key encrypted at rest and be able to actually delete it, that would work for me.
    
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