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Has anyone proposed proof of work for email? For instance force everyone who is sending to find a nonce that will take a few seconds per email? Should work just

Has anyone proposed proof of work for email? For instance force everyone who is sending to find a nonce that will take a few seconds per email? Should work just fine for you if you're sending mail manually or to a short list, but will take ages if you're spamming millions of people.

dwb 6y ago
Yes: https://en.wikipedia.org/wiki/Hashcash https://en.wikipedia.org/wiki/Hashcash
dagi3d 6y ago
I think it was Bill Gates who suggested that as well a loooong time ago way before blockchain/pow
- losvedir 6y ago
  Yeah, I remember reading this idea in the 90s in his book The Road Ahead. I thought it was such a cool idea, and was sad it never happened.
garmaine 6y ago
That is exactly what proof of work was invented to do. It’s the claim to fame of Adam Back, the current CEO of Blockstream. https://en.wikipedia.org/wiki/Hashcash https://en.wikipedia.org/wiki/Hashcash
chx 6y ago
https://craphound.com/spamsolutions.txt https://craphound.com/spamsolutions.txt Your post advocates a ( X ) technical ( X ) market-based approach to fighting spam. Your idea will not work. Here is why it won't work. (One or more of the following may apply to your particular idea, and it may have other flaws which used to vary from state to state before a bad federal law was passed.) ( X ) Mailing lists and other legitimate email uses would be affected ( X ) Requires immediate total cooperation from everybody at once Specifically, your plan fails to account for ( X ) Lack of centrally controlling authority for email ( X ) Public reluctance to accept weird new forms of money and the following philosophical objections may also apply: ( X ) Ideas similar to yours are easy to come up with, yet none have ever been shown practical ( X ) Sending email should be free Furthermore, this is what I think about you: ( X ) Sorry dude, but I don't think it would work.
- darkerside 6y ago
  Snarky but mostly accurate. I do take issue with: > Ideas similar to yours are easy to come up with, yet none have ever been shown practical Technology is constantly advancing in ways that are related to the problem domain in non-obvious ways, so repeating that old saw puts us in a reverse boiling frog situation. We never jump in the pot because it doesn't seem hot enough. Well, until someone ignores people saying things like this and does it anyway. > Mailing lists and other legitimate email uses would be affected Allowing people to "opt in" to emails from people and companies they support could help, but you're right that this becomes a "spam tax". Which I'm mostly ok with, despite working for a company that sends a LOT of email.
- timmaxw 6y ago
  Maybe I'm missing something, but none of these objections seem insurmountable. > Mailing lists and other legitimate email uses would be affected The receiving server could require proof-of-work for the first message from a sender to a given receiver, but not for subsequent messages. If spammers try to abuse this, it's easy for the user to click "block this sender"; if the spammer changes their sending address, they have to do a new proof-of-work. > Requires immediate total cooperation from everybody at once It could be introduced gradually: if a proof-of-work is provided, then the message is allowed to skip the spam filter. Small mailserver operators often have trouble with their messages being caught in spam filters by GMail and other large webmail providers; even if GMail alone started accepting proof-of-work, that would probably be enough to convince a lot of senders to start generating proofs-of-work, which would drive adoption. > Lack of centrally controlling authority for email This is no more difficult than any other backwards-compatible extension to an existing Internet standard. > Public reluctance to accept weird new forms of money OP's post didn't mention a weird new form of money. The original HashCash proof-of-work proposal included a weird new form of money, but it's easy to imagine a proof-of-work system that doesn't. > Sending email should be free Suppose the proof-of-work cost is calibrated such that it costs about $0.001 per email. That would be enough to destroy spammers' margins, but the vast majority of legitimate users wouldn't mind paying that. > Ideas similar to yours are easy to come up with, yet none have ever been shown practical I kinda see the point here... But I'd like to understand _why_ it isn't practical, because none of the arguments make sense to me.
dlubarov 6y ago
To add to the other replies, Vitalik had some ideas for spam deterrence based on proof of stake: https://ethresear.ch/t/conditional-proof-of-stake-hashcash/1301 https://ethresear.ch/t/conditional-proof-of-stake-hashcash/1...
dane-pgp 6y ago
Proof of work is basically equivalent to proof of money, but perhaps such a system would be reasonable with a few adjustments. Firstly, the financial burden should be on the owner of the SMTP server / domain, rather than on the users themselves. Of course, the owner would pass the costs onto their users, but the system doesn't have to require an ongoing fee, just a bond for good behaviour. (This could be done with cryptocurrency, a smart contract, and a "proof of burn" type of transaction). Secondly, and perhaps most importantly to encourage adoption, all existing registered domains should be grandfathered in, so they wouldn't have to put up a bond, whereas any future competitors would. Finally, and this is the controversial bit, there would have to be some set of entities who were able to determine whether a domain had acted in a way that should forfeit their bond (and, optionally, that a domain had acted in a positive way long enough that the bond should be refunded). In practice, though, such a cabal already exists, which is the Big Three email providers (Gmail, Outlook, Yahoo Mail). Together they already have the power to destroy any new email provider, so we might as well formalise that by giving them the power to burn these good behaviour bonds.
chx 6y ago
> Has anyone proposed proof of work for email? Yes, the first was approximately contemporary with dinosaurs roaming the earth, before NCSA Mosaic was released and images appeared in webpages also known as the year 1992. > We present a computational technique for combatting junk mail in particular and controlling access to a shared resource in general. The main idea is to require a user to compute a moderately hard, but not intractable, function in order to gain access to the resource, thus preventing frivolous use. https://link.springer.com/content/pdf/10.1007%2F3-540-48071-4_10.pdf https://link.springer.com/content/pdf/10.1007%2F3-540-48071-... Dwork C., Naor M. (1993) Pricing via Processing or Combatting Junk Mail. In: Brickell E.F. (eds) Advances in Cryptology — CRYPTO’ 92. CRYPTO 1992. Lecture Notes in Computer Science, vol 740. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-48071-4_10 https://doi.org/10.1007/3-540-48071-4_10

dwb 6y ago

Yes: https://en.wikipedia.org/wiki/Hashcash https://en.wikipedia.org/wiki/Hashcash

dagi3d 6y ago

I think it was Bill Gates who suggested that as well a loooong time ago way before blockchain/pow

losvedir 6y ago
Yeah, I remember reading this idea in the 90s in his book The Road Ahead. I thought it was such a cool idea, and was sad it never happened.

garmaine 6y ago

That is exactly what proof of work was invented to do. It’s the claim to fame of Adam Back, the current CEO of Blockstream. https://en.wikipedia.org/wiki/Hashcash https://en.wikipedia.org/wiki/Hashcash

chx 6y ago

https://craphound.com/spamsolutions.txt https://craphound.com/spamsolutions.txt Your post advocates a ( X ) technical ( X ) market-based approach to fighting spam. Your idea will not work. Here is why it won't work. (One or more of the following may apply to your particular idea, and it may have other flaws which used to vary from state to state before a bad federal law was passed.) ( X ) Mailing lists and other legitimate email uses would be affected ( X ) Requires immediate total cooperation from everybody at once Specifically, your plan fails to account for ( X ) Lack of centrally controlling authority for email ( X ) Public reluctance to accept weird new forms of money and the following philosophical objections may also apply: ( X ) Ideas similar to yours are easy to come up with, yet none have ever been shown practical ( X ) Sending email should be free Furthermore, this is what I think about you: ( X ) Sorry dude, but I don't think it would work.

darkerside 6y ago
Snarky but mostly accurate. I do take issue with: > Ideas similar to yours are easy to come up with, yet none have ever been shown practical Technology is constantly advancing in ways that are related to the problem domain in non-obvious ways, so repeating that old saw puts us in a reverse boiling frog situation. We never jump in the pot because it doesn't seem hot enough. Well, until someone ignores people saying things like this and does it anyway. > Mailing lists and other legitimate email uses would be affected Allowing people to "opt in" to emails from people and companies they support could help, but you're right that this becomes a "spam tax". Which I'm mostly ok with, despite working for a company that sends a LOT of email.
timmaxw 6y ago
Maybe I'm missing something, but none of these objections seem insurmountable. > Mailing lists and other legitimate email uses would be affected The receiving server could require proof-of-work for the first message from a sender to a given receiver, but not for subsequent messages. If spammers try to abuse this, it's easy for the user to click "block this sender"; if the spammer changes their sending address, they have to do a new proof-of-work. > Requires immediate total cooperation from everybody at once It could be introduced gradually: if a proof-of-work is provided, then the message is allowed to skip the spam filter. Small mailserver operators often have trouble with their messages being caught in spam filters by GMail and other large webmail providers; even if GMail alone started accepting proof-of-work, that would probably be enough to convince a lot of senders to start generating proofs-of-work, which would drive adoption. > Lack of centrally controlling authority for email This is no more difficult than any other backwards-compatible extension to an existing Internet standard. > Public reluctance to accept weird new forms of money OP's post didn't mention a weird new form of money. The original HashCash proof-of-work proposal included a weird new form of money, but it's easy to imagine a proof-of-work system that doesn't. > Sending email should be free Suppose the proof-of-work cost is calibrated such that it costs about $0.001 per email. That would be enough to destroy spammers' margins, but the vast majority of legitimate users wouldn't mind paying that. > Ideas similar to yours are easy to come up with, yet none have ever been shown practical I kinda see the point here... But I'd like to understand _why_ it isn't practical, because none of the arguments make sense to me.

dlubarov 6y ago

To add to the other replies, Vitalik had some ideas for spam deterrence based on proof of stake: https://ethresear.ch/t/conditional-proof-of-stake-hashcash/1301 https://ethresear.ch/t/conditional-proof-of-stake-hashcash/1...

dane-pgp 6y ago

Proof of work is basically equivalent to proof of money, but perhaps such a system would be reasonable with a few adjustments. Firstly, the financial burden should be on the owner of the SMTP server / domain, rather than on the users themselves. Of course, the owner would pass the costs onto their users, but the system doesn't have to require an ongoing fee, just a bond for good behaviour. (This could be done with cryptocurrency, a smart contract, and a "proof of burn" type of transaction). Secondly, and perhaps most importantly to encourage adoption, all existing registered domains should be grandfathered in, so they wouldn't have to put up a bond, whereas any future competitors would. Finally, and this is the controversial bit, there would have to be some set of entities who were able to determine whether a domain had acted in a way that should forfeit their bond (and, optionally, that a domain had acted in a positive way long enough that the bond should be refunded). In practice, though, such a cabal already exists, which is the Big Three email providers (Gmail, Outlook, Yahoo Mail). Together they already have the power to destroy any new email provider, so we might as well formalise that by giving them the power to burn these good behaviour bonds.

chx 6y ago

> Has anyone proposed proof of work for email? Yes, the first was approximately contemporary with dinosaurs roaming the earth, before NCSA Mosaic was released and images appeared in webpages also known as the year 1992. > We present a computational technique for combatting junk mail in particular and controlling access to a shared resource in general. The main idea is to require a user to compute a moderately hard, but not intractable, function in order to gain access to the resource, thus preventing frivolous use. https://link.springer.com/content/pdf/10.1007%2F3-540-48071-4_10.pdf https://link.springer.com/content/pdf/10.1007%2F3-540-48071-... Dwork C., Naor M. (1993) Pricing via Processing or Combatting Junk Mail. In: Brickell E.F. (eds) Advances in Cryptology — CRYPTO’ 92. CRYPTO 1992. Lecture Notes in Computer Science, vol 740. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-48071-4_10 https://doi.org/10.1007/3-540-48071-4_10