I don't think that ends up working for voting machines because those are two different problems. With the CDN, the user receives source code and they want to v

I don't think that ends up working for voting machines because those are two different problems. With the CDN, the user receives source code and they want to verify the source code is unchanged. Checking a hash of the data they received is sufficient. For a voting machine, what's the analogue? If I walk up to a voting machine with an integrity key, how do I check that the source code it's running has a given hash or is signed with a given key? If the voting machine itself shows the code or does the check, obviously a person who compromised the machine can fake that bit. If I have to remove the hdd and verify the data on it, and take apart the voting machine to verify there's no second hard drive... well, that seems like it's well out of reach of any voter verifying it. Integrity keys, hashes, signatures, blockchains, etc can verify digital data, can verify the contents of data that servers serve... But they don't seem to solve the problem of "what code is this machine running", and that seems to be the important problem for voting machine code.