In the news last month, a former Tesla owner discovered that his totaled vehicle (or at least its computer) were now driving in the Ukraine – with the new owner grooving to Drake on his Spotify playlist!

How did this happen? Isn’t data erasure on flash media a straightforward process?  

While we don’t know all the details of the vehicle scenario above, we do know that for embedded systems, successful data sanitization can be trickier than you might think. For data to be effectively removed from flash-based media, the secure erase method should be implemented. Otherwise, there is a real possibility that data remains in a readable format on the flash memory.  

As we’ve talked about in previous blog posts, secure erase is a set of protocols allowing an embedded designer to effectively erase and then overwrite the flash block the data was stored on – a combination that ensures sufficient data sanitization.  

Data lingers on flash media if not properly removed

An important factor that you will want to consider is when that data needs to be removed, especially if security is a concern. The infotainment stacks of newer vehicles often have access to a lot of personal data. When that vehicle changes owners, this must be dealt with properly. 

The last time I rented a car, I noticed a host of contacts that did not come from my Motorola. Even car share services, often with basic infotainment packages, will contain personal data from paired phones. 

Tablets and laptops can also change hands, and data should also be removed from any IoT device before it ends up being mined for precious metals. In some cases, a factory reset is sufficient. Below the function call, the NAND must be erased and then sanitized. 

Related content: 

Get a breakdown of secure data sanitization processes for NAND in our blog post, “The nuts and bolts of secure erase.” 

Improving data sanitization with flash memory management software

Securely erasing data also means erasing it immediately, even if the entire erase block isn’t filled. This contributes to flash memory wear, and can ultimately reduce the lifetime of the media. While it might not be an issue for erasing a few secure keys, maintaining security on a larger database of information may significantly hurt the media lifetime. 

A flash memory manager like Tuxera FlashFX Tera works with secure erase protocols to maximize flash memory lifetime while amplifying the sanitization efforts of secure erase. This is achieved through something called file system discards or trim commands. While we mentioned that secure erase aims to permanently wipe data by overwriting (after it has been deleted), discards are a far better solution. Discards help reduce wear on the flash memory, improving the lifetime of the media. 

Whitepaper: Keep device data safe with secure erase 

Our whitepaper, “Keep device data safe with secure erase,” goes into detail on the process of securely removing data from flash–based devices. While you may think this is something you can do at home, the paper demonstrates that deep knowledge of the flash translation layer or firmware is often required to completely remove any secure data. 

Final thoughts

Comprehensive, rigorous data removal can be a deciding factor in whether device data ends up in the wrong hands. While in some cases this means preventing an end user’s vehicle and spotify account from being taken for a mysterious ride, in other cases it means preventing highly sensitive data from being compromised.  

Tuxera has expertise in maximizing the security and lifetime of NAND media, with resources to help you figure out the best data storage management options for your system. Tuxera FlashFX Tera provides tools, such as discards, that when combined with secure erase protocols help achieve full data removal – ensuring any sensitive data on your media is securely dealt with. 

We are also working on a tech note with more details on how NAND is erased, which will drill down on what has recently been referred to as “zeroization”.