4 ms·

You don't. The same way that you don't ensure your recipient doesn't leak screenshots of signal conversations to icloud.

joshuamorton 7y ago
So your threat model is "protect me from my email provider (and very little else) assuming every person I interact with has great opsec"?
- buzzkillington 7y ago
  My threat model is the one that I learned at a three letter agency when I was organizing their key signing party.
  - joshuamorton 7y ago
    This appears to contradict your earlier comment, so I'm confused.
    - tsimionescu 7y ago
      I think the point was that you can't protect yourself from your recipient disclosing the information, regardless of your chosen scheme,so it just doesn't matter.
      - joshuamorton 7y ago
        There are schemes that make it difficult for a recipient to accidentally disclose your information. PGP isn't one of them. For example a common enough way of doing PGP is to use a chrome extension that PGP-ifies your webmail. Or to use an encrypted mail service like protonmail or tutanota. In all of those cases, assuming the mail provider is untrustworthy enough that you feel the need to use e2e encryption, they can also just inject JS to steal your plaintext from the client, so you aren't really secure unless you're using an imap client, which by definition you aren't doing.
        buzzkillington 7y ago
        >You don't. The same way that you don't ensure your recipient doesn't leak screenshots of signal conversations to icloud. Again, if your counter party is an idiot nothing will save you.
        joshuamorton 7y ago
        Good protocols prevent people from shooting themselves in the foot. A good protocol will get in your way if you try to do something insecure. PGP doesn't do that, see "oops I accidentally forwarded the plaintext of my encrypted email" vs. Gmail and Outlook's "confidential" modes, which prevent accidental exfiltration via forwarding or copying. They're possible to circumvent, but you have to make an effort to do it. PGP requires that you not only not be careless, but be near-perfect, and that every counterparty does the same. Good protocols prevent you from making mistakes that spew your plaintexts everywhere. In other words, I want a protocol that doesn't necessarily protect me from idiots, but does protect me from humans who occasionally act imperfectly.
        blacklion 7y ago
        It is not problem of protocol. It is problem of user agent. And, yes, all webmails is incredibly crappy user agents. Stop using webmails! On the other hand, UA (for any protocl) which will not allow copy'n'paste from is crappy by definition and nobody could stop your recipient to copy'n'paste plain text from your message. Ultimately, it is THEIR message as much as YOUR message! On the side note, I think that GMail is worst thing that has happened both to the web and to e-mail.
        GoblinSlayer 7y ago
        People don't share information in text anymore, they share screenshots and screen photos, it's infuriating.
        joshuamorton 7y ago
        Secure protocols ensure that user agents are secure, as part of the protocol. A secure protocol would, for example, not mix plaintext and encyrpted text messages, but would ensure that all messages were always encrypted. This way a we'll designed user agent couldn't accidentally mix cypher and plaintext messages. I'm not arguing that UAs should do user hostile things in the name of security, which is the straw man you're arguing against. Nor did I mention anything webmail specific. I'm saying that a security protocol shouldn't have, in practice, fail open attributes that user agents have to put warnings up about. A good protocol should allow the UA to entirely hide those dangers. This is abundantly clear if you try to use any pgp mail client vs any signal protocol client. The protocol makes it easier for UAs to be both more secure and more user friendly.

joshuamorton 7y ago

So your threat model is "protect me from my email provider (and very little else) assuming every person I interact with has great opsec"?

buzzkillington 7y ago
My threat model is the one that I learned at a three letter agency when I was organizing their key signing party.
- joshuamorton 7y ago
  This appears to contradict your earlier comment, so I'm confused.
  - tsimionescu 7y ago
    I think the point was that you can't protect yourself from your recipient disclosing the information, regardless of your chosen scheme,so it just doesn't matter.
    - joshuamorton 7y ago
      There are schemes that make it difficult for a recipient to accidentally disclose your information. PGP isn't one of them. For example a common enough way of doing PGP is to use a chrome extension that PGP-ifies your webmail. Or to use an encrypted mail service like protonmail or tutanota. In all of those cases, assuming the mail provider is untrustworthy enough that you feel the need to use e2e encryption, they can also just inject JS to steal your plaintext from the client, so you aren't really secure unless you're using an imap client, which by definition you aren't doing.
      - buzzkillington 7y ago
        >You don't. The same way that you don't ensure your recipient doesn't leak screenshots of signal conversations to icloud. Again, if your counter party is an idiot nothing will save you.
        joshuamorton 7y ago
        Good protocols prevent people from shooting themselves in the foot. A good protocol will get in your way if you try to do something insecure. PGP doesn't do that, see "oops I accidentally forwarded the plaintext of my encrypted email" vs. Gmail and Outlook's "confidential" modes, which prevent accidental exfiltration via forwarding or copying. They're possible to circumvent, but you have to make an effort to do it. PGP requires that you not only not be careless, but be near-perfect, and that every counterparty does the same. Good protocols prevent you from making mistakes that spew your plaintexts everywhere. In other words, I want a protocol that doesn't necessarily protect me from idiots, but does protect me from humans who occasionally act imperfectly.
        blacklion 7y ago
        It is not problem of protocol. It is problem of user agent. And, yes, all webmails is incredibly crappy user agents. Stop using webmails! On the other hand, UA (for any protocl) which will not allow copy'n'paste from is crappy by definition and nobody could stop your recipient to copy'n'paste plain text from your message. Ultimately, it is THEIR message as much as YOUR message! On the side note, I think that GMail is worst thing that has happened both to the web and to e-mail.
        GoblinSlayer 7y ago
        People don't share information in text anymore, they share screenshots and screen photos, it's infuriating.
        joshuamorton 7y ago
        Secure protocols ensure that user agents are secure, as part of the protocol. A secure protocol would, for example, not mix plaintext and encyrpted text messages, but would ensure that all messages were always encrypted. This way a we'll designed user agent couldn't accidentally mix cypher and plaintext messages. I'm not arguing that UAs should do user hostile things in the name of security, which is the straw man you're arguing against. Nor did I mention anything webmail specific. I'm saying that a security protocol shouldn't have, in practice, fail open attributes that user agents have to put warnings up about. A good protocol should allow the UA to entirely hide those dangers. This is abundantly clear if you try to use any pgp mail client vs any signal protocol client. The protocol makes it easier for UAs to be both more secure and more user friendly.