But how secure would that be? It's security through obscurity.
> Ultimately, these wireless control devices must simply be built with the assumption that hackers will eventually break in.
> In the case of the insulin pump, it should contain hardware-level sanity checking.
DRM is one thing, an encrypted wireless protocol is another. Think using WPA with user- or factory-settable keys to talk between the base/elements (I'm not sure how insulin pumps work).
Yes. Tell me the algorithm you use and the bits from your decryption key, and we can decrypt everything.
By the same token, the lock on your door is security by obscurity. Tell me the type of lock and the position of the 5 pins, and you're in. Take 5 seconds to communicate that over the phone, if you know what you're talking about.
The phrase "security through obscurity" is a term of art that is defined such that secrecy of private key material does not count. By definition, you are incorrect.
Now, if your security relies upon the attacker not knowing your encryption scheme, then yes. That is security through obscurity.
To expound slightly on burgerbrain's comment, this phrase is universally used to refer to schemes whose security relies critically on the suppression of information about the system. The term simply does not apply to strong encryption with configurable keys.
The term doesn't apply to door locks either, at least not in practice. If I were forever prevented from changing the locks on my house, then yes my security would depend critically on you never knowing about the key. In practice though, I can change the locks at will, and this is an effective remedy against the persistent threat posed by the release of the key.
A good example of security though obsurity is the CSS system used on DVDs, which was designed such that once the key was discovered, the system became forever and irretrievably broken.
> Ultimately, these wireless control devices must simply be built with the assumption that hackers will eventually break in. > In the case of the insulin pump, it should contain hardware-level sanity checking.