[sdiy] Lockout / DRM chips?

[David Kantowitz]

On Fri, Sep 11, 2026 at 12:22 AM cheater cheater <cheater00social at gmail.com>
wrote:

> > You can store databases on an untrusted device, but it's tricky.
>
> What's wrong with signing a piece of data and storing it on a flash
> chip? The cpu would know if it's been tampered with. Why would I need
> to hide data in random accesses?
>

Where I saw this type of technology used, the lists got *big*.  The
solutions I knew of were:
  1. Have enough memory with the secure module to hold the whole list.
 Always a problem after ~5 years
  2. Stream the entire list through the secure CPU.  Takes time.
  3. Have a query protocol with an untrusted local cpu that has much larger
memory.  These protocols are tricky.  For example, you must clearly
understand what happens if the untrusted computer responds with "nope, I
don't have that".  To help prevent this, hide your intentions in a storm of
requests.

Generally (1) was the choice because ... "gosh, sounds like you need to
upgrade to our latest model!"
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