> Securely erasing saved keys is just as important as generating them. It’s especially challenging to do so on flash storage, where wear-leveling might mean multiple copies of data need to be erased. To address this issue, iOS devices include a feature dedicated to secure data erasure called Effaceable Storage. This feature accesses the underlying storage technology (for example, NAND) to directly address and erase a small number of blocks at a very low level.
I guess that means separate storage, as the main storage in recent iPhones is an NVMe SSD and not raw NAND attached to the processor.
BTW, is there a good / easy way to connect raw NAND to a normal desktop PC?
What purpose do you want to access raw NAND? If you are okay with just a basic low speed connection to read the NAND, there is a fairly standardized async protocol which you could achieve with a dozen GPIO pins. You could also use a FPGA or and NAND flash programmer (like of like the old EPROM programmers)
However beyond this, you need to know a bit more information to interpret this raw data. This includes any data framing structure, error correction, scrambling, encryption and read error recovery algorithms. A lot of this information is non-standard or only available under NDA from the manufacturer.
In that case, I'm not familiar of any practical way to to interface to the NAND flash except that which comes with some embedded controllers boards. But let me add that even if you interface to the NAND, you still need to solve some of the things I mentioned above if the NAND is any technology node below 20nm or so. If you don't do it right, even with decent error correction you will get a high bit error rate.
> Securely erasing saved keys is just as important as generating them. It’s especially challenging to do so on flash storage, where wear-leveling might mean multiple copies of data need to be erased. To address this issue, iOS devices include a feature dedicated to secure data erasure called Effaceable Storage. This feature accesses the underlying storage technology (for example, NAND) to directly address and erase a small number of blocks at a very low level.
I guess that means separate storage, as the main storage in recent iPhones is an NVMe SSD and not raw NAND attached to the processor.
BTW, is there a good / easy way to connect raw NAND to a normal desktop PC?