Recover $220 Million Worth of Bitcoin Locked in a Self Destructing Hard Drive

Question

A NY Times article recently ran a story of Stefan Thomas who has $220 million worth of Bitcoin locked up in an encrypted hard drive:

Stefan Thomas, a German-born programmer living in San Francisco, has two guesses left to figure out a password that is worth, as of this week, about $220 million.

The password will let him unlock a small hard drive, known as an IronKey, which contains the private keys to a digital wallet that holds 7,002 Bitcoin.

I am familiar with this discussion on SE which analyzes possible vectors to retrieve the actual PK using brute force. However, in this specific case we are trying to retrieve the password, not of the actual Bitcoin wallet but of the hard drive. Once the password to the hard drive is found, the PK would be known automatically. The main issue is that the hard drive will self destruct after 10 failed password attempts (8 attempts have been tried so far in Stefan Thomas's case).

What possible vectors are available to retrieve Bitcoin in this case? My first thought was to copy the contents of the hard drive to many different drives and try to brute force each copy separately. This way when one hard drive self destructs you can always continue brute forcing on the other. Obviously, this won't be cheap but it might be worthwhile depending on how much Bitcoin is at stake. However, there might be something specifically about IronKey that prevents copying?

Is copying hard drive an effective/feasible strategy? If not, what other possible vectors should one consider to tackle this problem?

Thanks

Answer 1

I'm not sure on the specifics of this particular model, but usually the way these work is the encryption key is stored on a hardware security module, which is a physical chip that performs the encryption and decryption of the data given the right password.

To my knowledge you cannot make a copy of this physical chip, and once your attempts at entering the password run out, the chip will permanently wipe its copy of the encryption key. This chip is the thing that is checking your password, so it's this chip you would have to somehow duplicate.

With a lot of effort, you could probably desolder the flash memory chips and attempt to make a copy of the encrypted data itself. However, this encrypted data is generally protected with a 256-bit AES key (with has nothing to do with your password), of which the only copy was on the encryption chip, which the chip wiped when your password attempts ran out. So, this would be pointless.