From the other thread:
... but definitely the 100-200 range for a set (min 3) of them is likely, but there is still a bit of work to be done as it's not so simple as I originally thought so I would rather not quote prices.
Basically you've got it exactly right. There is a bitcoin private key inside the device (NOT INTENDED TO HOLD FUNDS) and a public key which is given to the users. The user then encrypts their own secret with the public key, or public key+salt and then stores the encrypted data on the chip. To get decrypt the encrypted data, they break the container open, get the private key, regenerate the public key, optionally add their salt, and decrypt the encrypted data on the chip.
I still have a difficult time to understand it.
On the one hand you say the user needs to break to glass to get to the key, but at the same time you say the user stores data on the chip. Isn't this contradicting?
If it really looks as it looks on the shiny preview pictures the price is dirt cheap.
But what I really want: a device that holds a seed - which is not known by you, but defined by me - for a deterministic wallet (
BIP 32). Bonus: device emmits public key to the seed, but doesn't emmit the seed. But I'd probably be already happy, if it's just a stupid RFID chip inside a shiny device which allows me to store and access something. In this case (without the need to break the glass to get the data), I'd use two: one to store the seed which is locked away and another one for "daily" use to generate new addresses.