Email encryption on Android and iOS becomes easy with the open source app Tutanota | Hacker News Reader

Email encryption on Android and iOS becomes easy with the open source app Tutanota

tutanota.de

33 pointsbruce48726 comments

Open articleView on HN

So, one can only send encrypted mails to other users of the platform?

http://tutanota.uservoice.com/knowledgebase/articles/470724-...

No, it works with anybody: http://tutanota.uservoice.com/knowledgebase/articles/470795-...

Yeah, it emails a link to the third party to use their website to read the email.

And you have to pre-share a password.

It basically takes a dump on every standard we already have.

That link only talks about pgp/gpg, but yeah - their solution (haven't figured out the whole thing yet) seems to be "Send everything to our servers, others can get it from there using our app (or a web application)".

No gpg/pgp relation. No IMAP support¹. They do support SMTP if

a) the recipient is not on the same platform

b) you're sending an unencrypted mail (only possible to external users anyway)

If you send an encrypted mail to an external user, they basically just get a link or something. "View the real mail here"?

I believe the intentions are good, but that's trying to solve the problem by killing off most things I require for my mails, unfortunately.

①: http://tutanota.uservoice.com/knowledgebase/articles/470761-...

The NSA Planned to Hijack Google App Store to Hack Smartphones [1]

Given that software updates are automatic (unless you manually turn them off etc), how can you trust an app if you can't trust the platform?

1. https://firstlook.org/theintercept/2015/05/21/nsa-five-eyes-...

Two things.

Firstly, Android checks app signatures and as far as I know the market app doesn't have any ability to override that. It can do a few privileged things like skip showing the permissions screen, but I think the OS still wants to see correct signatures. So even if the app store was hacked the phone itself might reject a bogus upgrade.

Secondly, that slide is more like some junior GCHQ guy noodling around, I think. It is old and dates from a time before Google used SSL for everything. I doubt it's possible to do via purely technical attacks now.

Thirdly, it'd almost certainly be easier to attack the developer laptop/workstation to steal the signing keys directly than attack Android head on. I plan to do some research this summer into splitting the RSA signing keys used by Android apps to allow for threshold signed online updates for Android and maybe iOS.

> It is old and dates from a time before Google used SSL for everything

Their budget is $52.6 billion and (as you say, the slides are old) they have lead time too. Let that sit for a moment.

The only way to change the signing key for an app (on an unrooted phone at least) is by completely uninstalling it (which deletes the main data directory) and then installing a new version. In fact, Google lost the key for their OTP authenticator app at one point, requiring all users to install the new app manually before they would receive updates again.

Have you got a link? I can't find any info on that happening

Couldn't find the blog post I read way back when it happened. The closest thing I could find was an Android news site describing the problem. [1]

I'm 90% sure that a Google engineer admitted it on their official blog, but that was 2 years ago so I might be misremembering it.

[1] http://www.androidpolice.com/2012/03/22/psa-googles-authenti...

I thought it was already easy on Android with K-9 and APG.

APG is discontinued. You should use OpenKeychain now instead - http://www.openkeychain.org - OpenKeychain does everything APG did, more, and has a much nicer interface. It even lets you use a Yubikey as a PGP smartcard over NFC so you don't have to store your PGP keys on your phone - https://grepular.com/An_NFC_PGP_SmartCard_For_Android

The one thing that K-9 misses, which is pretty major IMO, is PGP/MIME support. It only works with inline PGP.

Thanks for the information, I'll look into those.

Yeah, I don't like that PGP/MIME isn't supported, but I manage.

Slightly OT, but what's the likelihood of Apple/Google integrating PGP natively into the OS? I know iPhone has S/MINE - but is PGP too much to ask?

For PGP you can try:

https://whiteout.io/

https://lavaboom.com/

I don't know about Apple, but I doubt Google will because of the features they've been putting out lately (i.e.: Now cards for flights, etc based on emails).

This will never work. I'm more enthusiastic about DIME.[1]

I think SMTP will not (and cannot) ever be replaced. But if there will be DIME support in Postfix and Thunderbird, I can give it a chance.

[1] https://darkmail.info/

For submission, there's RFC 4468.

I have to be honest, I have given up on pgp. From what I know there is no way to have encrypted communications between more than two people. So why even bother pursuing the dream of everyone using it if there is such a roadblock in the way of common communication habits.

I believe PGP does support multiple recipients. The symmetric key is encrypted and included for every recipient.

Ouch, I did not expect that. Nice!

PGP absolutely supports multiple recipients. As the other reply says, the (small) symmetric key is encrypted separately with the public key of every recipient.

A good alternative is Countermail [https://countermail.com/] (probably more secure than Tutanova, to the extent possible for these services) and an app such as K-9 Mail.

Don't forget https://protonmail.ch They are working on iOS and Android apps, and from what I've seen they have the most promise of making encryption simple for ALL.

"Swiss Data Security

Our email service safeguards user data with strict privacy protections and our secure datacenter facility hidden inside a Swiss granite mountain."

Now that is comforting.

I might be missing something but the source of the actual iOS app doesn't appear to be on their Github.

Reply on news.ycombinator.com