Re: [Enigmail] Key management by users, and key use by Enigmail/GPGWin/etc.
On 06/08/14 16:24, Robert J. Hansen wrote: I do not get your point here. My proposal is to operate the keyring from a USB stick. What is the difference with operating it from a smart card? Exactly what I said. USB is completely broken as far as security goes. A USB device cannot be made secure. Thumb drives are malware vectors par excellence, and with some of the recent attacks which work by exploiting the firmware things get even nastier and harder to defend against. If you're concerned about a remote attacker exploiting your system from afar, you should also be concerned about a remote attacker rooting your box and exploiting the hell out of your USB stack. Smart cards work by storing the key in a method where it cannot be read by the host computer. Once a key is moved to the smart card, it ceases to exist as anything other than a black box. Data can be sent to the smart card to be decrypted or signed, but the host computer has literally no access to the cryptographic key stored on the smart card. In a USB model, an attacker who can compromise your box can easily acquire your private key: wait for you to plug in the USB dongle and make a covert copy of your keyring. In a smartcard model, an attacker can't easily acquire your private key. Does the recent news about vulnerability of usb devices to attacks such as described in 'badusb' [*] mean that the usb reader into which the gnupg smart card is inserted is also vulnerable to exploits ? If not, what is the essential difference that would make a usb memory stick compromisable but not the usb smart card reader ? [*] /srlabs.de/badusb/ 0x23543A63.asc Description: application/pgp-keys signature.asc Description: OpenPGP digital signature ___ enigmail-users mailing list enigmail-users@enigmail.net To unsubscribe or make changes to your subscription click here: https://admin.hostpoint.ch/mailman/listinfo/enigmail-users_enigmail.net
Re: [Enigmail] Key management by users, and key use by Enigmail/GPGWin/etc.
Does the recent news about vulnerability of usb devices to attacks such as described in 'badusb' [*] mean that the usb reader into which the gnupg smart card is inserted is also vulnerable to exploits ? Sure. But the *kind* of exploits are different. If not, what is the essential difference that would make a usb memory stick compromisable but not the usb smart card reader ? Not only did I already answer this, but you included it in your email (as a quote). Smart cards work by storing the key in a method where it cannot be read by the host computer. Once a key is moved to the smart card, it ceases to exist as anything other than a black box. Data can be sent to the smart card to be decrypted or signed, but the host computer has literally no access to the cryptographic key stored on the smart card. In a USB model, an attacker who can compromise your box can easily acquire your private key: wait for you to plug in the USB dongle and make a covert copy of your keyring. In a smartcard model, an attacker can't easily acquire your private key. ___ enigmail-users mailing list enigmail-users@enigmail.net To unsubscribe or make changes to your subscription click here: https://admin.hostpoint.ch/mailman/listinfo/enigmail-users_enigmail.net
Re: [Enigmail] Key management by users, and key use by Enigmail/GPGWin/etc.
-BEGIN PGP SIGNED MESSAGE- Hash: RIPEMD160 Hi Philip, Does the recent news about vulnerability of usb devices to attacks such as described in 'badusb' [http://srlabs.de/badusb/] mean that the usb reader into which the gnupg smart card is inserted is also vulnerable to exploits? Yes. ANY USB device. Personally, I don't use a USB based smart card reader ;-) If not, what is the essential difference that would make a usb memory stick compromisable but not the usb smart card reader ? No. The principle difference remains, even for USB based SmartCard readers: even if you hack the (USB based) SmartCard reader, you still are not able to get hold of the secret stored within your private key since this key is even generated in the card, it literally only exists within that card and is only accessible (in terms of being used to compute something) through the card OS commands. Olav - -- The Enigmail Project - OpenPGP Email Security For Mozilla Applications -BEGIN PGP SIGNATURE- Version: GnuPG v2.0.22 (MingW32) Comment: Dies ist eine elektronische Signatur - http://www.enigmail.net/ iQGcBAEBAwAGBQJT45LpAAoJEKGX32tq4e9WET8L/Rxr5JtPbLdF6yhBZmRzJoTz bA/MfKyvK4Uccgq9BEu1Bce60T//SE0uQsLtaRo2qCNOLolUkVOl6630ujTLH+9s TAwFH8UShi3WP6dRgndE9GBS3w6rmygDK2DPkLpUMUBslTyCJtfvz92egR3cScVZ 0NTW2rHSf4pZxieK2KWXLAbq4+epnn7xbvTAFqbUVVQEuwk4BklcSoXYMXksihs9 RQfn1dnXviwLLxPh2S1GiYH/jsAYwjXaHA478tZgnLA/ThmrZm0yH3QpjChew/fu peC4vf2vHCVf64+NslAWLgdRTe42OgIdHEivTXYztYhhRgURx0h5khZ1uR8mB4V3 nbNEZoFJhY/4JuRIo3iJEQoIEJzFIPXayUaESQmFVhebETh12BIblXXCPakEu/B4 Q/nLbMHgEkUPysHOOv7XGetYIvonuu8puSmg9L9OFVQqHUIRAVyBZsyW5X+w0Vzq SFz1Z0xAD7QX4I3TAo0HZDscCN+iL9mLL8/AjhPExw== =Da2t -END PGP SIGNATURE- ___ enigmail-users mailing list enigmail-users@enigmail.net To unsubscribe or make changes to your subscription click here: https://admin.hostpoint.ch/mailman/listinfo/enigmail-users_enigmail.net
