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Suppose one wants to use email (say using protonmail with Tor Browser / obfs4 bridges) to discuss sensitive matters (such as asylum seeking / embassy protection) with embassy in potentially hostile foreign countries.


To be more precise,

  • Adversary: Potentially hostile foreign government governing the place I am living in, which may control a number of email servers.
  • Resources: This country is a middle to great power. I could be on their watch list, but only as a small potato.
  • Nonadversary: protonmail and embassy
  • Threats: Adversary read my correspondence with embassy and take actions before I do.

Is my actions safe at all? AFAIK, email is unencrypted. Can email servers in the middle read my email? How do governments secure their [SEC=OFFICIAL] emails?

In the perfect world, we should be able to contact embassy using Signal with E2EE, but we are not there yet...

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  • "safe" from what? That needs to be defined.
    – schroeder
    Aug 7 at 19:00
  • 3
    Messages would be encrypted in transit from your browser to protonmail's server. Protonmail would have access to the plaintext of the messages once they reach protonmail's server. Message would be encrypted in transit from protonmail's server to emabssy's MX server (assuming embassy's MX is configured for STARTTLS). Embassy's MX would have access to plaintext of messages. Embassy would presumably fetch the messages from embassy's MX via a secure (POP3, IMAP, or HTTPS) connection. If you want a more secure E2E transport - you might want to see if embassy is setup for PGP or similar.
    – mti2935
    Aug 7 at 20:48
  • @schroeder I edited to clarify threat model.
    – user264384
    Aug 8 at 16:25
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In some potentially hostile foreign countries using Tor can be enough to alert security services. They cannot know the content of your exchanges, nor even what destination you will connect, but they do know that you want it to be secret.

Said differently, your proposal is certainly as safe as current technology allows on an information exchange point of view. Whether it is safe on a real life point of view (the one where you could end in a jail) is a fully different problem and depends on usages of the country where you live.

Any security analysis shall begin with:

  • who are the potential adversaries and what are their resources
  • what are the threats
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  • I should have mentioned I also hide the use of Tor using obfs4 bridges :) For your questions regarding my threat model. Adversary: Potentially hostile foreign government governing the place I am living in, which may control a number of email servers. Resources: Assume this country is a middle to great power. Nonadversary: protonmail. Threats: Adversary read my correspondence with embassy and take actions before I do.
    – user264384
    Aug 8 at 16:07
  • I edited to clarify threat model.
    – user264384
    Aug 8 at 16:25

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