A new risk, if the chip is locked by KEY, then the board is worthless unless you know the key, it have no second-hand value like GPU
The key doesn't prevent unencrypted designs from running. Keep in mind, if we didn't do this it would also open an attack vector where a developer could maliciously burn the efuse preventing any designs from operating but their own.
I'm pretty sure you were already told this on discord?
no, i did not talk on discord, i review it. also i found the pdf,xapp1267,eFuse is OTP,it can lock the chip to a key.
So if you reviewed the documentation you would know that the chip can still load unencrypted bitstreams (assuming you use the correct options).
Once the key is loaded, yes, the key cannot be changed.
The ram key is wiped when the board loses power. The board doesn't have a battery.
if you control the software,you can use another way to protect your work.NO EFUSE ,NO battery RAM needed.
1.when board begin to run ,it gen a random number,and append your secretive key1,then SHA2(or others algo) it
2.software read the hash message,send to a server,(the miner is online,so it is easy to connect the server)
3.the server append the hash with your secretive key2,then SHA2(or others algo) it ,send back
4.the board check the result,if match ,run miner,otherwise ,do nothing.
so ,you just need two key,
every new developer or new algo can have his own key,
also the boards will not lose their value.