3 ms·

Right, but then you should store it "in a chip designed against physical attacks", as the person you replied to mentioned.

sowbug 9y ago
That isn't a panacea. Even though secure elements today have clever defenses against physical attack, they're no match against a sufficiently-funded adversary. Contrast cryptography, where no amount of money or human effort could defeat, say, 256-bit symmetric encryption. The reason this matters is that if you accept that defeating physical defenses is always a matter of money, then you must next decide the attack cost that's sufficiently high to protect your assets. Then when you learn that the cost to defeat any hardware wallet, including Trezor, is already very high, you understand that we might as well be debating the merits of 255- vs. 256-bit encryption. (Note that this is not meant to draw an equivalence between hardware Bitcoin wallets and modern symmetric cryptography. There is a big difference. But not a difference that improves the infeasibility of mounting an attack against your Trezor with 25 BTC in it.)
- londons_explore 9y ago
  If I had 250 BTC (half a million dollars), I would be quite confident that someone would try to steal it if a simple power supply glitching trick could extract it. Whereas if it is in a physically protected chip (like many credit card chips), I would feel rather safe knowing the tech and expertise to extract it costs more than half a million dollars.
  - sowbug 9y ago
    We're in agreement on the general idea of a cost-benefit analysis for security, but your numbers are a bit off. 250BTC is worth over $1M USD (especially if you owned it as of Aug 1 and thus also have 250 Bitcoin Cash). Breaking into your house to steal a hardware wallet has a significant cost/risk in many people's minds. If someone is willing to break into your house, they're probably also willing to beat you senseless until you transfer them your bitcoin, because you surely value it less than your own life. That's why I think the cost to defeat hardware is high in general, but not especially relevant if your threat model includes targeted attacks.

sowbug 9y ago

That isn't a panacea. Even though secure elements today have clever defenses against physical attack, they're no match against a sufficiently-funded adversary. Contrast cryptography, where no amount of money or human effort could defeat, say, 256-bit symmetric encryption. The reason this matters is that if you accept that defeating physical defenses is always a matter of money, then you must next decide the attack cost that's sufficiently high to protect your assets. Then when you learn that the cost to defeat any hardware wallet, including Trezor, is already very high, you understand that we might as well be debating the merits of 255- vs. 256-bit encryption. (Note that this is not meant to draw an equivalence between hardware Bitcoin wallets and modern symmetric cryptography. There is a big difference. But not a difference that improves the infeasibility of mounting an attack against your Trezor with 25 BTC in it.)

londons_explore 9y ago
If I had 250 BTC (half a million dollars), I would be quite confident that someone would try to steal it if a simple power supply glitching trick could extract it. Whereas if it is in a physically protected chip (like many credit card chips), I would feel rather safe knowing the tech and expertise to extract it costs more than half a million dollars.
- sowbug 9y ago
  We're in agreement on the general idea of a cost-benefit analysis for security, but your numbers are a bit off. 250BTC is worth over $1M USD (especially if you owned it as of Aug 1 and thus also have 250 Bitcoin Cash). Breaking into your house to steal a hardware wallet has a significant cost/risk in many people's minds. If someone is willing to break into your house, they're probably also willing to beat you senseless until you transfer them your bitcoin, because you surely value it less than your own life. That's why I think the cost to defeat hardware is high in general, but not especially relevant if your threat model includes targeted attacks.