Ok Google: please publish your DKIM secret keys • Hacker News Board

Re: Ok Google: please publish your DKIM secret keys

#281

Post by GoblinSlayer » Mon, Nov 16, 2020, 9:30 PM UTC

baobabKoodaa wrote: post #232

hyperpape wrote: post #198

Earlier quoted context omitted.

As you know, there are many legitimate needs to publish naked pictures of your body to the entire internet, but most people want to keep them private. Defaults matter. What makes this hard is that email is responsible for too much crap. No single user interface should carry: 1. Party invites 2. Private messages to your spouse, therapist, pastor, etc. 3. Marketing messages 4. Password recovery requests 5. Financial tr…

I agree that e-mail is horrible, and I would prefer if contracts (like purchase receipts) moved off e-mail to something else, but that's tangential to the point. If Google started to publish and rotate DKIM keys, the world wouldn't suddenly move away from email.

Receipts can be signed with gnupg, it actually provides non-repudiation guarantee you want, DKIM doesn't provide that, it's only for journalists.

Re: Ok Google: please publish your DKIM secret keys

#282

Post by im3w1l » Mon, Nov 16, 2020, 9:30 PM UTC

baobabKoodaa wrote: post #75

tptacek wrote: post #55

Earlier quoted context omitted.

Among messaging cryptographers, it's not even an argument. Serious secure messengers have been designed to avoid non-repudiation since OTR. Non-repudiation is a vulnerability: once counterparties have authenticated each other's messages, the legitimate need for authentication is gone; allowing random strangers to authenticate messages concedes information to them. Here, have a link, from 2004: https://otr.cypherpunks…

> once counterparties have authenticated each other's messages, the legitimate need for authentication is gone; allowing random strangers to authenticate messages concedes information to them. As you know, there are many legitimate needs to authenticate messages of strangers. For example, when you order products over the internet, an e-mail of your purchase is often the only proof of what was agreed in the purchase.…

Yeah the man-off-the-street expects that if you have an email in your inbox it's proof positive that it was received like that. They don't know that you can upload counterfeit emails using imap or anything like that.

Introducing non-repudiation would violate everyone's expectations and create a total mess.

I'm saying this as someone who often and deliberately uses deniable messengers.

Re: Ok Google: please publish your DKIM secret keys

#283

Post by ryanmarsh » Mon, Nov 16, 2020, 9:32 PM UTC

The persons used as examples for justification for publishing and rolling DKIM are exactly the kind of people whom I do not want to have the benefit of repudiation. If they did something bad, it's in the public interest to prove so.

Re: Ok Google: please publish your DKIM secret keys

#284

Post by geocar » Mon, Nov 16, 2020, 9:32 PM UTC

creeble wrote: post #256

The problem with the author's paper is that his assumption (and that of, apparently, media organizations, Wikileaks, and others) of DKIM "ensuring non-repudiation of emails" is simply wrong. >DKIM provides a life-long guarantee of email authenticity that anyone can use to cryptographically verify the authenticity of stolen emails, even years after they were sent. No, it doesn't. It simply offers an assurance that, at…

I don't think it needs to be all server operators;

It is not difficult for me to believe a Judge could find it "unlikely" that a 2013 email was forged containing a valid Google signature, and I would not want to rely on you being on my jury. If Google were to publish their private keys, I could produce a forgery of my own in my defence.

Of course it would be great if people were smarter than they are, but they're not, and I wrote some perl today, so it is hard to tilt at this particular windmill.

Re: Ok Google: please publish your DKIM secret keys

#285

Post by ivanhoe » Mon, Nov 16, 2020, 9:33 PM UTC

avianlyric wrote: post #115

ivanhoe wrote: post #95

Earlier quoted context omitted.

True, there are things that might ruin someone's life even though there's nothing bad about them, but the list of actual crimes and bad things that people do is WAY longer, and being able to prove it is definitely useful...

The same argument can be used to build a police state. But I suspect that you’re not in favour that either. We shouldn’t be building technical systems that “trap” people, just because they might be doing something bad and might want to prove that one day. Additionally you’re also ignoring the whole “people have the right, to not have their emails stolen” argument. DKIM signatures are only useful if the emails are sto…

> Additionally you’re also ignoring the whole “people have the right, to not have their emails stolen” argument

No, just the opposite, that is an excellent argument and I think that the privacy should be the real focus when we discuss the freedom, and not the accountability. Because freedom is not to be able to get away for the lack of evidence, freedom is not to put innocent people in that kind of situation in the first place.

Police state doesn't come from the ability to track citizens, it comes from the lack of transparency and government's misuse of the information. Now, reality is that having more data collecting increases the chances of misuse, but I think we're attacking the problem from the wrong side. Rather than killing the option to track emails, there should be much more control and transparency on when and how that data can be collected and used.

Re: Ok Google: please publish your DKIM secret keys

#286

Post by XCSme » Mon, Nov 16, 2020, 9:35 PM UTC

If anyone is interested, I recently wrote a short article about email verifying (DKIM, DMARC, SPF) after someone else used my domain name to send some not-so-nice emails: https://www.usertrack.net/blog/stop-others-use-your-domain-e...

Re: Ok Google: please publish your DKIM secret keys

#287

Post by ryanmarsh » Mon, Nov 16, 2020, 9:35 PM UTC

tarkin2 wrote: post #140

I'm torn. But someone could threaten to speak to your insurer about a medical condition mentioned in an email.

Your concern is that insurers (presumably medical?) will used hacked emails to set your rates?

Re: Ok Google: please publish your DKIM secret keys

#288

Post by timmytokyo » Mon, Nov 16, 2020, 9:38 PM UTC

tptacek wrote: post #82

I know threads change over time, and it's dangerous to write a comment in response to the perceived gestalt of an HN thread, but, I have to say, it's pretty wild reading a thread on this site arguing so strenuously against the premise of secure messaging. In messaging cryptography, non-repudiability has for almost 2 decades been considered a vulnerability, not a feature. The OTR protocol[1] takes the step of publishi…

I think the reason there's so much controversy about this post is because it was written in the context of a recent political controversy around which tribes have formed unusually strong opinions. It's hard to have a quality technical discussion when so many of the participants are being driven more by tribal emotions than by rational discussion.

Re: Ok Google: please publish your DKIM secret keys

#289

Post by josephg » Mon, Nov 16, 2020, 9:42 PM UTC

tptacek wrote: post #199

saurik wrote: post #189

Earlier quoted context omitted.

FWIW, I am pretty sure I agree with you/OTR, but the IETF Messaging Layer Security (MLS) people disagree for not-always-trivially-dismissible reasons (indirect link because I am lazy). https://news.ycombinator.com/item?id=25101825

(a) I wasn't aware of this. (b) Thanks for the link! (c) The IETF is such a shitshow for cryptography.

The IETF is an open organisation. Specs are written & ratified by the people who show up. And often that means folks from large companies.

If you don’t like that status quo, get involved. They would love to have you @tptacek.

Re: Ok Google: please publish your DKIM secret keys

#290

Post by baobabKoodaa » Mon, Nov 16, 2020, 9:48 PM UTC

hamburglar wrote: post #242

baobabKoodaa wrote: post #240

Earlier quoted context omitted.

> the sender should just add non-repudiation to it in the form of a signature that's intended for that. Simple. Ok, but this does not magically happen if Google publishes and rotates their DKIM keys. People will continue to use email for everything, but now emails can no longer be authenticated by third parties.

I think the entire point is that non-repudiation shouldn't just magically happen unless intended, so yes, this is by design, and anyone who wants to send a signed email should explicitly send a signed email.

> I think the entire point is that non-repudiation shouldn't just magically happen unless intended, so yes, this is by design, and anyone who wants to send a signed email should explicitly send a signed email.

Let's not pretend that the world would move away from email if Google made this change. We both know that's not going to happen. Given that, can you explain why you think the world would be a better place when emails can be repudiated? When emails can be not be repudiated, innocent people can be framed for saying/doing things that they didn't do. DKIM protects innocent people from being framed. DKIM also protects innocent people against guilty people who commit frauds or other crime.