Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Skiff – Privacy-first end-to-end encrypted email

skiff.com

Post reply on HN
Print view View original

21–30 of 201 posts

Re: Skiff – Privacy-first end-to-end encrypted email

#21

Post by tptacek »

From the white paper, it appears as if this system requires its users to trust the server. That's not end-to-end encryption. What do I have wrong here?

Further, it looks like the email encryption provided by this system only works between users of Skiff. At that point, why use email at all? Why not use a real secure messenger? Instead of building an "encrypted email service", you could literally just build an email-flavored frontend to Matrix; either way, you're proxying to SMTP, not speaking it directly.

Re: Skiff – Privacy-first end-to-end encrypted email

#22

Post by LWIRVoltage »

Looked into this, ...it looks interesting.

..Personally, this looks promising. I am going to say it though- Skiff needs some sort of mechanism to use PGP if for nothing else, then to communicate with Protonmail email addresses specifically. I see they are taking the stance its's time to move to something beyond PGP- but given the extremely large userbase that is Protonmail- I think their target market would feel better being able to communicate with their protonmail contacts- using PGP.

Also, i'm having trouble seeing if Skiff has a way to 'send secure emails' to other external email providers, like Tutanota ,Mailbox, and Protonamil do for their users to securely contact people outside their ecosystems(like peeps with gmail). Solve those issues- and the pain/difficulty/unease of convenience will disappear for their market which likely already uses Protonmail/Tutanota, etc. And Skiff would be very attractive at that point, positioning itself as a successor to those two possibly.

Re: Skiff – Privacy-first end-to-end encrypted email

#23

Post by tptacek »

LWIRVoltage wrote: post #22

Looked into this, ...it looks interesting. ..Personally, this looks promising. I am going to say it though- Skiff needs some sort of mechanism to use PGP if for nothing else, then to communicate with Protonmail email addresses specifically. I see they are taking the stance its's time to move to something beyond PGP- but given the extremely large userbase that is Protonmail- I think their target market would feel bett…

This is a system that appears to have long-term identity keys, for which "forward security" or "forward secrecy" appears a total of zero times in its white paper. If this is an improvement on PGP, it's not totally clear to me how. Maybe one of its authors will clear that up.

Re: Skiff – Privacy-first end-to-end encrypted email

#24

Post by amilich »

LWIRVoltage wrote: post #22

Looked into this, ...it looks interesting. ..Personally, this looks promising. I am going to say it though- Skiff needs some sort of mechanism to use PGP if for nothing else, then to communicate with Protonmail email addresses specifically. I see they are taking the stance its's time to move to something beyond PGP- but given the extremely large userbase that is Protonmail- I think their target market would feel bett…

I definitely agree, we are considering what to do here. I think there is a lot to improve with PGP (https://latacora.micro.blog/2019/07/16/the-pgp-problem.html), but I agree with the problem.

Right now, you can use Skiff Pages for this. You can share public links that have E2EE using link fragments, add passwords, and collaborate in real-time.

Re: Skiff – Privacy-first end-to-end encrypted email

#26

Post by esdf »

LWIRVoltage wrote: post #22

Looked into this, ...it looks interesting. ..Personally, this looks promising. I am going to say it though- Skiff needs some sort of mechanism to use PGP if for nothing else, then to communicate with Protonmail email addresses specifically. I see they are taking the stance its's time to move to something beyond PGP- but given the extremely large userbase that is Protonmail- I think their target market would feel bett…

openpgp web key directory exists and should work but I don't know if many email providers support or use it

Re: Skiff – Privacy-first end-to-end encrypted email

#27

Post by wishywashy0 »

tptacek wrote: post #21

From the white paper, it appears as if this system requires its users to trust the server. That's not end-to-end encryption. What do I have wrong here? Further, it looks like the email encryption provided by this system only works between users of Skiff. At that point, why use email at all? Why not use a real secure messenger? Instead of building an "encrypted email service", you could literally just build an email-f…

Founding engineer at Skiff here.

>From the white paper, it appears as if this system requires its users to trust the server. That's not end-to-end encryption. What do I have wrong here?

It doesn't. All data is encrypted client side across all apps - Skiff Mail, Drive, Pages, and Calendar. For sending external, the whitepaper is very clear how this case is handled in section 8.2 as securely as possible (without having PGP in place. Though this is something we are looking at based on community feedback).

>Further, it looks like the email encryption provided by this system only works between users of Skiff. At that point, why use email at all? Why not use a real secure messenger? Instead of building an "encrypted email service", you could literally just build an email-flavored frontend to Matrix; either way, you're proxying to SMTP, not speaking it directly.

Lots of folks are sick of getting sold their data sold based on their email. Even corporations are sick of largely giving more information about their customers to Google even notoriously Amazon that stopped sending purchase receipts via email.

So even if not end to end encrypted, we do encrypt the emails with the recipient's keys ensuring that only the recipient can access this data. This is a strong privacy guarantee not just backed by a flimsy privacy policy but actual cryptography.

Re: Skiff – Privacy-first end-to-end encrypted email

#29

Post by tptacek »

wishywashy0 wrote: post #27
tptacek wrote: post #21

From the white paper, it appears as if this system requires its users to trust the server. That's not end-to-end encryption. What do I have wrong here? Further, it looks like the email encryption provided by this system only works between users of Skiff. At that point, why use email at all? Why not use a real secure messenger? Instead of building an "encrypted email service", you could literally just build an email-f…

Founding engineer at Skiff here. >From the white paper, it appears as if this system requires its users to trust the server. That's not end-to-end encryption. What do I have wrong here? It doesn't. All data is encrypted client side across all apps - Skiff Mail, Drive, Pages, and Calendar. For sending external, the whitepaper is very clear how this case is handled in section 8.2 as securely as possible (without having…

Section 8.2 seems to talk about how you send plaintext email via SMTP to users who aren't using Skiff.

But that's not what I'm talking about with respect to end-to-end encryption. The white paper refers repeatedly to "browser" users. Your server can feed arbitrary Javascript to browsers and subvert encryption in a variety of ways, can't it?

I'm still not clear why you designed a new, simplistic cryptosystem at all here; can't you do everything you're trying to do here on top of Matrix? Again: the cryptography promises you're making only work between users of your system.

Post reply on HN