[tigger0jk]

People who are protected from blackmail by email repudiation are by definition people who have incriminating emails. Maybe everyone had skeletons in their closet, but if you have email proof of skeletons I'm starting to wonder if you're such a good person.

Also there's an argument that "good people" can be blackmailed for INVENTED misconduct, but wouldn't such fake emails be more convincing without the ability to verify their origins? Making real emails and fake emails more similar protects people who have their incriminating emails leaked, but it also harms the defence of people who have fake emails targeting them "leaked".

There's a high bar for obfuscating truth and I don't believe this argument meets it.

[avianlyric]

Ah yes, the good old, “If you haven’t done anything wrong, you’ve got nothing to hide” argument. The authoritarians favourite argument for a police state.

I guess you’re the type of person that would happily hand over all your personal files to the police on a regular basis as you have nothing to hide.

[tigger0jk]

To be clear, the reason I was presenting that is that the OP says the opposite, essentially "You have to fear being blackmailed, even if you have done nothing wrong". I'm suggesting that non-repudiation is actually a good defense against blackmail for people who have "done nothing wrong". thinkharderdev provides a more concrete example of one of the problems that arises in the police state, in that "wrong"-ness is not consistent, and you could be persecuted for things you say or who you are based on a backwards interpretation of what is "wrong".

Personally I am fine with the idea (as represented in this comment https://news.ycombinator.com/item?id=25115654) that email is providing something similar to a "paper trail", and when you send an email you can expect that people can prove you sent it, should they get their hands on the email. However, I totally understand the position that private secure messaging is important and that email should default to that.

In the authoritarian argument, "you've got nothing to hide", is followed by "you are now forced to reveal all", in my execution it would be "you are accountable for all emails you send, forever, should they be released". I am ok with that specific lack of privacy in that context, but I can understand the position that non-repudiability should be opt-in, and privacy the default.

[avianlyric]

I find this a little ironic

> that email is providing something similar to a "paper trail"

because paper doesn’t provide non-repudiation and never has done.

The whole point of a “paper trail” is the “trail” bit, as it provides providence of a sequence of actions or communications that logically fit together. Hopefully providing evidence for your side of a dispute.

There’s no need for email to be non-repudiatable to achieve this. In fact I serious doubt a court would care if an email is DKIM signed. Very rarely are disputes so simple and straightforward that proving a single email was sent is enough to produce an outcome.

In short DKIM non-repudiation by default gives up everyones privacy, to protect a tiny group of individuals engaged in extra edge case disputes, where the entire outcome of the disputes hangs on the validity of a single email.

[zo1]

Not OP. But I would give all my data to the police/government... in an encrypted manner that has guarantees in place that only valid criminal investigations can decrypt. Heck, we do it on some level all the time anyways when it comes to things such as filing taxes, getting married, running companies, enforcing contracts and various other day-to-day benign interactions.

At this point, I'm more inclined to believe that "democratic" and "noble" governments and agents are the ones maliciously pushing for "privacy" because it suits their power-maintaining agenda. I'm struggling to find compelling and valid reasons why we can't pursue a general solution that involves us giving all this "private" data to a government entity for legitimate investigations, fraud prevention and crime-solving whilst keeping that data free from abuse.

[earthboundkid]

> I'm struggling to find compelling and valid reasons why we can't pursue a general solution that involves us giving all this "private" data to a government entity for legitimate investigations, fraud prevention and crime-solving whilst keeping that data free from abuse.

Because that's not logically possible. It would be nice if it were, but just think about it: if you give data to the government, humans can look at it. Can we ensure that the humans who look at it are good humans? No. Is there some mathematical way of signing and encrypting such that only good humans can look at it? No.

Okay, so it's logically impossible to keep bad people out mathematically, but maybe it's a practical problem and it doesn't matter in practice? Except no, there are tons of evil governments (CCP being the most obvious, but pick your poison), and even good governments are subject to the problem that people can bribed and secrets can be stolen if there is sufficient motivation. It's just not compatible with human nature to say "collect all this information on people, but only use it For Good Purposes."

[CJefferson]

But, the message you are replying to points out governments already have piles of information about you -- your taxes for example. They can easily add to this (in appropriate legal situations), by reaching out to banks in your country for example.

While I understand the problem of evil governments, I broadly trust mine. I want them to have the power to investigate me, and my fellow citizens, for crimes. I don't want to love in a lawless country.

[earthboundkid]

The level of information we are talking about is not comparable.

First of all, tax information in the United States was in fact abused by Richard Nixon, so it's not just a hypothetical possibility. It's a thing that already happened and requires safeguarding to prevent recurring. If there were a way of collecting taxes without the possibility of abuse, we would use it, but there's not, so we do what we can to balance things. FWIW, I think actually a lot of government records should be stored on paper and not in computers because hackers can steal 300m records overnight, but even very enterprising thieves can only steal one or two truckloads of physical records per hour.

Second of all, this information is just on another level. My tax information is basically not interesting to anyone except that it has my SSN on it, and SSNs are only interesting because the US has bad laws around "identity theft" and we don't properly punish corporations for giving out loans based on nothing but an unverified SSN. Could someone embarrass me by releasing my tax info? I guess if they really dug into my charitable deductions and found an embarrassing cause (a la Brendan Eich?) or that I was giving too little? For me, an average American, there is little or no reason to fear having my taxes used against me.

Email is just not like that. There are certainly emails I have send and received which I hope no one else will see. It's just not comparable at all. It's the difference between having $100 in your wallet (might be stolen but probably not) and $6m in your wallet (will absolutely be stolen if people know about it).

Should the government be able to investigate me? Of course! But investigations have happened for centuries before emails existed. Investigation does not require pre-surveillance of emails or covert surveillance. The simplest thing the government can do is arrest me on suspicion of X charges and then go through all my computers. That is 100% the government should be able to do! If they catch me destroying evidence, I should be charged with destruction of evidence. But that is different from empowering the government to secretly look at email. The part where the government collects my email should be public action that I am well aware, not a secret action done passively by breaking encryption.

[avianlyric]

Do you trust all future governments?

Germany 1933, Donald Trump today, far right extremism in Europe are all examples of how trustworthy governments become evil governments.

Democracy doesn’t offer a defence against “evil” governments. Only that you need a majority (and frequently not even a majority) to vote for one.

[CJefferson]

I'm not clear what you are arguing for? Do you not want a functioning, effective police force now, in case they become evil in the future (or already are evil, depending on your point of view)?

If a government turns full evil, they don't need evidence against you, they can just lock you up without charge.

[avianlyric]

How exactly would you do this?

> in an encrypted manner that has guarantees in place that only valid criminal investigations can decrypt

What constitutes a valid criminal investigation, who decides? Do you, does a prosecutor, a judge, the police?

Is it a valid to decrypt your data just see if you were at a specific location at a specific time? What about so the police can check a theory? How about to see if you joined an unsanctioned protest, smoked a joint, speed while driving, downloaded a movie?

Speeding and copyright theft are both criminal, are you saying that your happy to make it trivial to investigate you for these crimes an prosecute you for them?

It used to be criminal to engage in homosexual behaviour, and in some parts of the world. Once upon a time that would be a valid criminal investigation in the US. For a short while it was looking like abortions might become criminal in the not too distant future.

Privacy is a fundamental tool for allowing society to progress and change, and for avoiding totalitarianism.

[zo1]

>"What constitutes a valid criminal investigation, who decides? Do you, does a prosecutor, a judge, the police?"

Some sort of formal process with reasonable oversight the necessity of multiple points of compromise and/or collusion in order for the data to be abused for non-governmental use. Bottom line, I can't say I've "solved" the problem and have the perfect answer to your question. But I'm sure we, collectively as a society filled with smart people that want to move us forward, could put down some (fundamental?) tools/rules/processes that would negate the potential for abuse up until a certain point. Maybe we can't do 100%, but we could do 95 or 98%?

>"Is it a valid to decrypt your data just see if you were at a specific location at a specific time? What about so the police can check a theory? How about to see if you joined an unsanctioned protest, smoked a joint, speed while driving, downloaded a movie?"

Yes, very much so Yes! Especially the location based stuff as it's perfect for investigations without revealing details. "List all people that were within 50m of this crime location during this timespan." <-- that is so unbelievably powerful as a crime-solving tool, that I am baffled that we're avoiding it out of privacy concerns. As for the speeding example: That's probably another example of us already giving the data (car's black-box) to government (and private insurance companies) in order to facilitate an investigation.

But to your point about drug-use, speeding and copyright infringement. If we don't want something prosecuted then we shouldn't have it as a crime. But as it stands now, a bunch of what you mentioned is a crime. That represents an implicit agreement by all of us in society that says we deem those things punishable. We can't hide behind lack of capability to police said crimes, but still label them as such. That is ripe for offical-power abuse. For all we know, if we lived in a society where we had such strict enforcement of laws as I suggest, we'd potentially have greater churn and change in our laws to match the opinions of society as it changed and evolved.

> "Privacy is a fundamental tool for allowing society to progress and change, and for avoiding totalitarianism."

I disagree. I'm not seeing it. There is just way too much going wrong today in 1-st world countries whilst we have really good privacy for it to be the case. We're downright descending into totalitarianism and thought/opinion control territory, all whilst our "privacy" is mostly maintained and respected. Are you saying we need more of it? What would that look like to you?

[avianlyric]

Here is an example of how location data can be abused, accidentally or otherwise [0]. If you go down this road, then smart criminals will just take steps to avoid carry location tracking devices. What do you do then? Force everyone to carry and maintain a GPS tracker? Arrest them if they fail to charge it properly, because they could use that window to commit a crime without being tracked?

> We can't hide behind lack of capability to police said crimes, but still label them as such.

Most laws are written with the implicit assumption it’s not possible to perfectly enforce them. That provides some natural wriggle room to interpret the laws, avoids the need to write a long list of when it’s ok to speed for example.

Perfect enforcement breaks all of that. A knowledgable police officer could almost certainly stop you on any day the week and find you guilt of some obscure and ancient crime that’s no longer relevant.

> For all we know, if we lived in a society where we had such strict enforcement of laws as I suggest, we'd potentially have greater churn and change in our laws to match the opinions of society as it changed and evolved.

How do you imagine society would evolve its opinions and change them in a world of perfect enforcement? How the gay community show the world there nothing wrong with their way of life, if they simply couldn’t live it?

How would society change its views on smoking weed, if it was impossible to smoke it?

It’s impossible for a society to change its view on existing laws, if it’s completely unable to experiment with ignoring, or re-interpreting them.

It would be like expecting a child to ask for food they had never eaten, and never seen anyone else eat. How could they possibly know it existed, much less if it was good or bad for them?

> I disagree. I'm not seeing it. There is just way too much going wrong today in 1-st world countries whilst we have really good privacy for it to be the case. We're downright descending into totalitarianism and thought/opinion control territory, all whilst our "privacy" is mostly maintained and respected

Hahahaha, seriously. You complain of thought control, but advocate for world where the government can watch your every move, and perfectly enforce every law. Have you read 1984? I see little difference between world in that book, and the one your advocating for.

> Are you saying we need more of it? What would that look like to you?

Yes I am. How can you control someone’s though and opinions if you don’t know what they are? How can a totalitarian government rule with an iron fist if they don’t know where their citizens are, or what they’re doing?

Totalitarian governments come into existence because people want control and order, and they’re great if you fit into that governments view of what control and order look like. If you don’t, we’ll there are plenty of genocides that can be studied.

[0] https://www.google.com/amp/s/www.theverge.com/platform/amp/2...

[int_19h]

Because we don't trust the government agents to provide such guarantees, or to honor them if they do?

[thinkharderdev]

I don't think the implication that only "bad" people can be blackmailed is valid. You could be blackmailed for being a homosexual in many parts of the US still or doubting the existence of god or having unacceptably conservative political views. We do all sorts of things that are not at all wrong but may carry a significant social or economic cost if they were to be exposed publicly.

[anfilt]

I think people are overlooking this. It can even be worse in other countries. Some of those things (among numerous other things) can lead to death in a few countries.

[scarmig]

The world isn't entitled to knowing whether something I'm alleged to have said or done really happened or not.

For the people who lack imagination: suppose I'm a public official, and a photograph comes out depicting me doing some kind of "dirty" sexual act. Maybe it's real; maybe it's a deepfake; but if confirmed to be real it certainly would do reputational damage. Non-repudiation by definition prevents me from disavowing it, to no social benefit, and it's an anti-feature, in the sense that the large majority of users would prefer to have the ability to repudiate certain message contents than not.

Non-repudiation should be opt-in.

[harikb]

Please read the whole article. If it only takes a "few hours" to create incriminating "evidence" (read, something that didn't exist) - it must be clearly proclaimed as such to the world.

[tigger0jk]

I believe you are referring to this quote (correct me if not): "In fact, in the early DKIM configurations were kind of a joke: mail providers chose DKIM signing keys that were trivial for motivated attackers to crack. Back in 2012 a security researcher named Zachary Harris pointed out that Google and several other companies were using using 512-bit RSA to sign DKIM. He showed that these keys could be “cracked” in a matter of hours on rented cloud hardware, and then used these keys to forge emails from Larry and Sergey.

Providers like Google reacted to the whole “Larry and Sergey” embarassment in the way you’d expect. Without giving the implications any serious thought, they quickly ramped up their keys to 1024-bit or 2048-bit RSA. This stopped the forgeries, but inadvertently turned a harmless anti-spam protocol into a life-long cryptographic authenticity stamp — one that can be used to verify the provenance of any email dump, regardless of how it reaches the verifier."

Note that the "few hours" attack here is only relevant if they were using easily crackable 512-bit keys. The author of this article suggests (and I agree) that the 1024 or 2048 bit RSA keys are not easily crackable. (see https://crypto.stackexchange.com/a/42830)

Maybe you are suggesting that someone could sign emails using the old crackable 512-bit keys. And they could, although we should disregard this as "not verification" given the weak keys. The article links to https://github.com/robertdavidgraham/hunter-dkim#short-dkim-... - which verifies an email using a since-rotated 2015 key (which was 2048 bits), although that github erroneously states that Google was using 1024 bit before that (they were using 512).

I would concede that the notion of "sometimes we should disregard some DKIM verifications based on the key length" is not easy to grasp and that email verification stories in the media could become muddier and harder to present. I would hope that interviewing experts gets you a reasonable estimation of how likely an email is to be legitimate.