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People who are protected from blackmail by email repudiation are by definition people who have incriminating emails. Maybe everyone had skeletons in their close

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.

harikb 6y ago
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 6y ago
  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 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-keys-can-be-cracked 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.
avianlyric 6y ago
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.
- zo1 6y ago
  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 6y ago
    > 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."
scarmig 6y ago
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.
thinkharderdev 6y ago
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 6y ago
  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.

harikb 6y ago

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 6y ago
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 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-keys-can-be-cracked 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.

avianlyric 6y ago

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.

zo1 6y ago
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 6y ago
  > 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."

scarmig 6y ago

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.

thinkharderdev 6y ago

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 6y ago
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.