Bitcoin2013 Speakers: Include your PGP fingerprint in your slides
5 messages, 14 May 2013. Started by Peter Todd.
Peter Todd (2), Melvin Carvalho, Harald Schilly, Adam Back
report: https://bitcointalk.org/index.php?topic=205349.0
Every talk will be widely witnessed and videotaped so we can get some reasonably good security by simply putting out PGP fingerprints in our slides. Yeah, some fancy attacker could change the videos after the fact, but the talks themselves will have wide audiences and a lot of opportunities for fraud to be discovered. That means it'd also be reasonable for people to sign those keys too if you are present and are convinced you aren't looking at some impostor. (of course, presenters, check that your PGP fingerprints are correct...)
Remember that PGP depends on the web-of-trust. No single measure in a web-of-trust is needs to be absolutely perfect; it's the sum of the verifications that matter. I don't think it matters much if you have, say, seen Jeff Garzik's drivers license as much as it matters that you have seen him in a public place with dozens of witnesses that would recognize him and call out any attempt at fraud.
Secondly remember that many of us are working on software where an attacker can steal from huge numbers of users at once if they manage to sneak some wallet stealing code in. We need better code signing practices, but they don't help without some way of being sure the keys signing the code are valid. SSL and certificate authorities have advantages, and so does the PGP WoT, so use both.
FWIW I take this stuff pretty seriously myself. I generated my key securely in the first place, I use a hardware smartcard to store my PGP key, and I keep the master signing key - the key with the ability to sign other keys - separate from my day-to-day signing subkeys. I also PGP sign emails regularly, which means anyone can get a decent idea of if they have the right key by looking at bitcoin-development mailing list archives and checking the signatures. A truly dedicated attacker could probably sign something without my knowledge, but I've certainly raised the bar.
On 14 May 2013 20:41, Peter Todd <pete@petertodd•org> wrote:
Quoted text (37 lines)
> report: https://bitcointalk.org/index.php?topic=205349.0 > > Every talk will be widely witnessed and videotaped so we can get some > reasonably good security by simply putting out PGP fingerprints in our > slides. Yeah, some fancy attacker could change the videos after the > fact, but the talks themselves will have wide audiences and a lot of > opportunities for fraud to be discovered. That means it'd also be > reasonable for people to sign those keys too if you are present and are > convinced you aren't looking at some impostor. (of course, presenters, > check that your PGP fingerprints are correct...) > > > Remember that PGP depends on the web-of-trust. No single measure in a > web-of-trust is needs to be absolutely perfect; it's the sum of the > verifications that matter. I don't think it matters much if you have, > say, seen Jeff Garzik's drivers license as much as it matters that you > have seen him in a public place with dozens of witnesses that would > recognize him and call out any attempt at fraud. > > Secondly remember that many of us are working on software where an > attacker can steal from huge numbers of users at once if they manage to > sneak some wallet stealing code in. We need better code signing > practices, but they don't help without some way of being sure the keys > signing the code are valid. SSL and certificate authorities have > advantages, and so does the PGP WoT, so use both. > > > FWIW I take this stuff pretty seriously myself. I generated my key > securely in the first place, I use a hardware smartcard to store my PGP > key, and I keep the master signing key - the key with the ability to > sign other keys - separate from my day-to-day signing subkeys. I also > PGP sign emails regularly, which means anyone can get a decent idea of > if they have the right key by looking at bitcoin-development mailing > list archives and checking the signatures. A truly dedicated attacker > could probably sign something without my knowledge, but I've certainly > raised the bar. >
Just out of curiosity, could PGP keyservers suffer from a similar 51% attack as the bitcoin network?
Quoted text (18 lines)
> > -- > 'peter'[:-1]@petertodd.org > 000000000000016be577c0f0ce4c04a05fdbfc8e0b6f69053659f32aeea3a518 > > > ------------------------------------------------------------------------------ > AlienVault Unified Security Management (USM) platform delivers complete > security visibility with the essential security capabilities. Easily and > efficiently configure, manage, and operate all of your security controls > from a single console and one unified framework. Download a free trial. > http://p.sf.net/sfu/alienvault_d2d > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists•sourceforge•net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > >
On Tue, May 14, 2013 at 09:16:28PM +0200, Melvin Carvalho wrote:
Quoted text (13 lines)
> > FWIW I take this stuff pretty seriously myself. I generated my key > > securely in the first place, I use a hardware smartcard to store my PGP > > key, and I keep the master signing key - the key with the ability to > > sign other keys - separate from my day-to-day signing subkeys. I also > > PGP sign emails regularly, which means anyone can get a decent idea of > > if they have the right key by looking at bitcoin-development mailing > > list archives and checking the signatures. A truly dedicated attacker > > could probably sign something without my knowledge, but I've certainly > > raised the bar. > > > > Just out of curiosity, could PGP keyservers suffer from a similar 51% > attack as the bitcoin network?
What guarantees do you think a keyserver provides about the keys it returns?
On Tue, May 14, 2013 at 9:16 PM, Melvin Carvalho <melvincarvalho@gmail•com> wrote:
Quoted text (2 lines)
> Just out of curiosity, could PGP keyservers suffer from a similar 51% attack > as the bitcoin network?
Well, no, and yes. It doesn't work like that.
If you have your own domain, you can store your key there as a TXT entry.
$ dig +short harald._pka.schil.ly. TXT
and even use it automatically: $ gpg … --auto-key-locate pka -r email@address•domain
H
On Tue, May 14, 2013 at 09:39:46PM +0200, Harald Schilly wrote:
Quoted text (6 lines)
>If you have your own domain, you can store your key there as a TXT entry. > >$ dig +short harald._pka.schil.ly. TXT > >and even use it automatically: >$ gpg … --auto-key-locate pka -r email@address•domain
Nice. But we all kow about the security of DNS ;)
Adam