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If you require a touch, challenge response behaves exactly same as smart card. In both cases, the database is locked, until you touch where the database is expo

by aborsy 5y ago

If you require a touch, challenge response behaves exactly same as smart card. In both cases, the database is locked, until you touch where the database is exposed in either case.

lrvick 5y ago
Hardware Authentication != Hardware Decryption In challenge response, your password manager has a cosmetic software control that prompts you to authenticate yourself with your Yubikey before it will expose the decryption key which in turn exposes your entire password database. This does not help you in the event your system is compromised, as an attacker would just have a background job that waits until the next time you authenticate and steal all secrets just after. When you use a true hardware encryption solution like Password Store with a Yubikey, it actually encrypts every single secret as individual blobs to a asymmetric public key in the Yubikey. The encryption key never once comes in contact with system memory. Instead a single requested secret is sent to the Yubikey, the decryption is done there in isolated memory and CPU, and then that single plaintext secret is sent back to the OS, provided the user touched the device. To summarize, let's assume your system is compromised with a rootkit by a remote actor. You have 100 secrets stored in both Keepass with Yubikey authentiction, and in Password Store with Yubikey encryption. To steal all your secrets from Keypass they only need to wait for you to tap your Yubikey once to get all 100 secrets, if that. They could just skip that check after all as it is just cosmetic. They have root and can modify any binary they want. Meanwhile in the Password Store setup to get all your 100 secrets your adversary has to trick you into tapping your Yubikey 100 times. Presumably you would notice something was up and have some damage control.
- aborsy 5y ago
  This is an important point, and I have written similar comments on HN (about this and other advantages of Pass). Keepass is per database vs GPG is per password. However, it’s not much related to the cryptography. You could write per password databases in keepassxc too, set each with CR and access by command line. You would need one touch per password. Yes, the key and crypto are inside Yubikey with GPG, whereas with CR only the key is inside Yubikey. We can debate which one is better, at the end it’s a second factor used in different ways.

by aborsy 5y ago

If you require a touch, challenge response behaves exactly same as smart card. In both cases, the database is locked, until you touch where the database is exposed in either case.

lrvick 5y ago

Hardware Authentication != Hardware Decryption In challenge response, your password manager has a cosmetic software control that prompts you to authenticate yourself with your Yubikey before it will expose the decryption key which in turn exposes your entire password database. This does not help you in the event your system is compromised, as an attacker would just have a background job that waits until the next time you authenticate and steal all secrets just after. When you use a true hardware encryption solution like Password Store with a Yubikey, it actually encrypts every single secret as individual blobs to a asymmetric public key in the Yubikey. The encryption key never once comes in contact with system memory. Instead a single requested secret is sent to the Yubikey, the decryption is done there in isolated memory and CPU, and then that single plaintext secret is sent back to the OS, provided the user touched the device. To summarize, let's assume your system is compromised with a rootkit by a remote actor. You have 100 secrets stored in both Keepass with Yubikey authentiction, and in Password Store with Yubikey encryption. To steal all your secrets from Keypass they only need to wait for you to tap your Yubikey once to get all 100 secrets, if that. They could just skip that check after all as it is just cosmetic. They have root and can modify any binary they want. Meanwhile in the Password Store setup to get all your 100 secrets your adversary has to trick you into tapping your Yubikey 100 times. Presumably you would notice something was up and have some damage control.

aborsy 5y ago
This is an important point, and I have written similar comments on HN (about this and other advantages of Pass). Keepass is per database vs GPG is per password. However, it’s not much related to the cryptography. You could write per password databases in keepassxc too, set each with CR and access by command line. You would need one touch per password. Yes, the key and crypto are inside Yubikey with GPG, whereas with CR only the key is inside Yubikey. We can debate which one is better, at the end it’s a second factor used in different ways.