21–30 of 31 posts
"To encrypt a File:" gpg -o encrypted_file.gpg –encrypt -r original.file # they didn't put recipient after -r ?
gpg -e file
The output will be file.gpg. It will ask you for a recipient unless you have "default-recipient" or "default-recipient-selt" set in gpg.conf.
Earlier quoted context omitted.
Multiple -r's: gpg -e -r recipient1@example.com -r recipient2@example.com That products some ciphertext which can be decrypted by either recipient.
Thank you. Does it weaken the encryption strength ?
Earlier quoted context omitted.
btw, how is a person signing a key in the usual WoT model supposed to know whether or not the email address specified in the key uid is actually controlled by the person standing in front of them at the key signing party with passport and key fingerprint in hand? Even if you carefully follow the recommended key signing procedure the binding which actually matters for exchanging encrypted email has very poor validatio…
Best practice is to send an encrypted message to that address in order to confirm the owner controls it.
If the author meant actually sending someone a email to see that it is indeed owned by them remotely: NO WAY. Does not work:
me: "hey, just sending you an email to confirm its really you before sending the secret plans?"
them: "yeah, its me. send the plans."
That is exactly what WoT tries to solve but can't due to misuse.
On all the encryption tutorials I found they always assume 2 and only 2 people trying to talk privately. I wonder how would one encrypt a conversation between say 15 people.
Multiple -r's: gpg -e -r recipient1@example.com -r recipient2@example.com That products some ciphertext which can be decrypted by either recipient.
Earlier quoted context omitted.
Best practice is to send an encrypted message to that address in order to confirm the owner controls it.
If you only meant verifying the email as apart of a keysigning party, agreed. Meaning you are looking at their passport and sending an email at the same time. This is better than nothing but wont protect against many directed attacks. For instance, a journalists has to be more careful. Also, in the end if you are sitting in front of each other might as well just verify key fingerprints. Better privacy and security th…
What kind of attacks is this practice vulnerable to?
Earlier quoted context omitted.
Lots of GPG themed sites do not. Notice that key servers provide web access over plain HTTP as well. My best guess is that they do not want to buy into the CA infrastructure and provide security using GPG itself. Also check out MonkeySphere.
> My best guess is that they do not want to buy into the CA infrastructure and provide security using GPG itself. This may be true (I really have no idea) but isn't it like travelling on a highway at night with your normal lights turned off because you have a better system based on infrared? After reading about the story of that guy who hacked into a computer by MITMing the notepad++ site, I became even more convince…
Earlier quoted context omitted.
Thank you. Does it weaken the encryption strength ?
No. The symmetric key that is used to encrypt the message is itself encrypted once for every recipient with their respective public keys, so the only difference is filesize (for most intents and purposes negligable). Of course, more recipients equals more targets for an attacker.
This is especially significant if the recipients have different sized public keys. If you send a message to a 2048-bit key and a 1024-bit key, the message only has 1024 bits of security. So you really do get a weakest link effect.
Earlier quoted context omitted.
If you only meant verifying the email as apart of a keysigning party, agreed. Meaning you are looking at their passport and sending an email at the same time. This is better than nothing but wont protect against many directed attacks. For instance, a journalists has to be more careful. Also, in the end if you are sitting in front of each other might as well just verify key fingerprints. Better privacy and security th…
I think you misunderstand. After meeting someone and exchanging public key fingerprints, you verify their identity. This requires checking their government ID and making sure they really are who they say they are. Then, you verify the uid of their key by sending them a message encrypted with the figerprint you received in person. Only the holder of both that key and the email address can respond to your message. Then…
> What kind of attacks is this practice vulnerable to?
So long as the trust only translates to the very limited use cases then there is no vulnerability. Those limits basically mean that no trust should be assumed by anyone that did not participate in the WoT in question. This particular style of WoT means anyone wanting to retain anonymity needs to skip it, or am i missing something?
Mainly I think all WoT models i've seen thus far are too susceptible to sybil attacks (impersonation) and as a result instill bad habits.
you only need to look at people use of pgp today to see how much WoT's would be a failure if used. pgp.mit.edu still aint got ssl. journalists are linking to nonssl links for their key via twitter t.to urls
Earlier quoted context omitted.
Multiple -r's: gpg -e -r recipient1@example.com -r recipient2@example.com That products some ciphertext which can be decrypted by either recipient.
I learned this the hard way when using gpg+mutt back in 2001. All my Sent mail was being encrypted only with the recipient's key, so I couldn't read it myself. There's an option to also encrypt outgoing email with your own GPG key.
"encrypt-to YOUR_KEY_ID"
in your gpg.conf
Earlier quoted context omitted.
Specifically "check a signature". Even everyone that knows how to sign fail to really check anything. Honestly, if it aint boiled down to a green or red icon then people are going to misuse, assume security when its not, or just click "yes". If you get a new public key for someone, and it's signed by someone else you don't know (most of the time this is the case) are you going to bother to utilise that signature to i…
I use PGP extensively. However, I haven't bothered with the web of trust, for the same reason I don't publish my address book for everyone to read, privacy.
Maybe I am mistaken or maybe there's a way to do that without having multiple keyrings or something, but that's kind of the problem. It's really hard to tell what I would or would not be sharing because there's no "interface" to speak of and I am hardly an expert.