5 ms·

> Tutanota is the end-to-end encrypted mail client that enables you to communicate securely with anyone. Is this promising end-to-end encryption over email eve

by Flimm 10y ago

> Tutanota is the end-to-end encrypted mail client that enables you to communicate securely with anyone. Is this promising end-to-end encryption over email even if one of the two parties is not using Tutanota?

x1798DE 10y ago
Looks to me like no: https://tutanota.uservoice.com/knowledgebase/articles/470785 https://tutanota.uservoice.com/knowledgebase/articles/470785 There is some voodoo in there about them storing your unencrypted mail encrypted on their server, but from that diagram it looks like it's only end to end between people registered with Tutanota (it looks like they may also allow federation, since they mention "or another service").
- troublord 10y ago
  Tutanota never stores unencrypted mails on the server. If you send an encrypted mail to an external recipient, the recipient will receive a link to his end-to-end encrypted mailbox. He can open his encrypted mailbox only with the passphrase that you (the sender) shared with him.
  - x1798DE 10y ago
    I would certainly hope that no one stores unencrypted mail on their servers, but that's just a "promise not to look" situation, not an "impossible to look" situation. As for the "encrypted mailbox", what you are describing sounds to me like the decryption is done client-side using javascript (unless the recipient needs to download something in order to decrypt the mail), in which case I would consider that to be essentially insecure anyway, as that is also a "promise not to look". It's the same situation as Protonmail, which I personally consider to be crypto snakeoil.
    - troublord 10y ago
      Just use a local client, if you do not want to trust Tutanota for delivering the code as published on github. You can use apps (iOS and Android) and even compile and install the client locally if you want to. There will also be apps for Windows and MacOS in the future.
      - x1798DE 10y ago
        I'm not sure what you mean by a local client. If you are suggesting that even the Tutanova users are decrypting things using browser crypto, that's absurd. I assumed this was all done either with a local client or a browser extension. If you mean that the non Tutanova user should have to install a Tutanova client, I might as well just have them set up PGP. If you mean a local server using the github code, it's a fair enough point - it's more complicated and likely insecure than using PGP, but at least the burden of complexity and security falls on the power user.
  - dingaling 10y ago
    > He can open his encrypted mailbox only with the passphrase that you (the sender) shared with him. Presumably that passphrase would be shared out-of-band to prevent Tutanota peeking, at which point... Why bother sending an e-mail at all?
deleted 10y ago
[deleted]
mr_sturd 10y ago
If you send an email to someone without Tutanota. They email the recipient with a link to their server. Allowing the recipient to decrypt the email in the browser, using a password agreed on, by the communicating parties.[0] [0]-https://tutanota.uservoice.com/knowledgebase/articles/470795-how-do-i-send-an-encrypted-email-to-an-external-re https://tutanota.uservoice.com/knowledgebase/articles/470795...
- skrowl 10y ago
  If I'm going to go the route of sharing a password, why wouldn't I just put a .txt or .html file with my email body in a password-protected/encrypted .7z or .zip and just send it with plain old gmail? My buddy doesn't have to change his email provider or click on any special links. In addition to not having forward secrecy (if a 3rd party gets his crypto password, they get ALL of my messages to him), this seems to fail the classic "In order to exchange a secret, first exchange a secret" crypto usability test.

by Flimm 10y ago

x1798DE 10y ago

Looks to me like no: https://tutanota.uservoice.com/knowledgebase/articles/470785 https://tutanota.uservoice.com/knowledgebase/articles/470785 There is some voodoo in there about them storing your unencrypted mail encrypted on their server, but from that diagram it looks like it's only end to end between people registered with Tutanota (it looks like they may also allow federation, since they mention "or another service").

troublord 10y ago
Tutanota never stores unencrypted mails on the server. If you send an encrypted mail to an external recipient, the recipient will receive a link to his end-to-end encrypted mailbox. He can open his encrypted mailbox only with the passphrase that you (the sender) shared with him.
- x1798DE 10y ago
  I would certainly hope that no one stores unencrypted mail on their servers, but that's just a "promise not to look" situation, not an "impossible to look" situation. As for the "encrypted mailbox", what you are describing sounds to me like the decryption is done client-side using javascript (unless the recipient needs to download something in order to decrypt the mail), in which case I would consider that to be essentially insecure anyway, as that is also a "promise not to look". It's the same situation as Protonmail, which I personally consider to be crypto snakeoil.
  - troublord 10y ago
    Just use a local client, if you do not want to trust Tutanota for delivering the code as published on github. You can use apps (iOS and Android) and even compile and install the client locally if you want to. There will also be apps for Windows and MacOS in the future.
    - x1798DE 10y ago
      I'm not sure what you mean by a local client. If you are suggesting that even the Tutanova users are decrypting things using browser crypto, that's absurd. I assumed this was all done either with a local client or a browser extension. If you mean that the non Tutanova user should have to install a Tutanova client, I might as well just have them set up PGP. If you mean a local server using the github code, it's a fair enough point - it's more complicated and likely insecure than using PGP, but at least the burden of complexity and security falls on the power user.
- dingaling 10y ago
  > He can open his encrypted mailbox only with the passphrase that you (the sender) shared with him. Presumably that passphrase would be shared out-of-band to prevent Tutanota peeking, at which point... Why bother sending an e-mail at all?

deleted 10y ago

[deleted]

mr_sturd 10y ago

If you send an email to someone without Tutanota. They email the recipient with a link to their server. Allowing the recipient to decrypt the email in the browser, using a password agreed on, by the communicating parties.[0] [0]-https://tutanota.uservoice.com/knowledgebase/articles/470795-how-do-i-send-an-encrypted-email-to-an-external-re https://tutanota.uservoice.com/knowledgebase/articles/470795...

skrowl 10y ago
If I'm going to go the route of sharing a password, why wouldn't I just put a .txt or .html file with my email body in a password-protected/encrypted .7z or .zip and just send it with plain old gmail? My buddy doesn't have to change his email provider or click on any special links. In addition to not having forward secrecy (if a 3rd party gets his crypto password, they get ALL of my messages to him), this seems to fail the classic "In order to exchange a secret, first exchange a secret" crypto usability test.