4 ms·

Very cool. I'll definitely subscribe and watch for how this progresses. I'll like that it is minimal but still have display. Unfortunately if someone controls u

by hdhzy 9y ago

Very cool. I'll definitely subscribe and watch for how this progresses. I'll like that it is minimal but still have display. Unfortunately if someone controls user machine they still can spoof the destination address so it's still possible to sign a bad transaction (as noted in the FAQ).

lisper 9y ago
Yes, that's true, but this is no different than any hardware wallet that obtains transactions to sign through a client machine. In fact, if you think about it, this must be the case. However, such an attack would be very difficult to actually carry out because it's not enough for the attacker to send the transaction to the SC4-HSM. The attacker also has to somehow trick you into pushing the button on the HSM. So the probably have to 1) time their attack to exactly coincide with you wanting to sign a transaction, 2) trick your client into thinking the HSM has sent it the proper handshake and 3) hope you don't notice that the value on the HSM display is wrong. It's possible, but really really hard to do without being noticed.
- runeks 9y ago
  Why not display the destination address, so the user can check whether this corresponds with what is expected? The device itself can easily check whether the change address belongs to its own private key, simply by requiring the online computer to provide the key index of the change address, and the device deriving this key to make sure it owns it.
  - lisper 9y ago
    > Why not display the destination address, so the user can check whether this corresponds with what is expected? Well, yeah, of course. What did you think it would do? > The device itself can easily check whether the change address belongs to its own private key Well, yeah, but how does that help? Usually you want to send money to other people (i.e. to keys you don't own), no?

4 ms·

Very cool. I'll definitely subscribe and watch for how this progresses. I'll like that it is minimal but still have display. Unfortunately if someone controls u

by hdhzy 9y ago

lisper 9y ago
Yes, that's true, but this is no different than any hardware wallet that obtains transactions to sign through a client machine. In fact, if you think about it, this must be the case. However, such an attack would be very difficult to actually carry out because it's not enough for the attacker to send the transaction to the SC4-HSM. The attacker also has to somehow trick you into pushing the button on the HSM. So the probably have to 1) time their attack to exactly coincide with you wanting to sign a transaction, 2) trick your client into thinking the HSM has sent it the proper handshake and 3) hope you don't notice that the value on the HSM display is wrong. It's possible, but really really hard to do without being noticed.
- runeks 9y ago
  Why not display the destination address, so the user can check whether this corresponds with what is expected? The device itself can easily check whether the change address belongs to its own private key, simply by requiring the online computer to provide the key index of the change address, and the device deriving this key to make sure it owns it.
  - lisper 9y ago
    > Why not display the destination address, so the user can check whether this corresponds with what is expected? Well, yeah, of course. What did you think it would do? > The device itself can easily check whether the change address belongs to its own private key Well, yeah, but how does that help? Usually you want to send money to other people (i.e. to keys you don't own), no?