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As a cypherpunk, when I first heard of bitcoin I was incredulous. But after many months of research and experimentation I became satisfied that the bitcoin prot

by joshuak 13y ago

As a cypherpunk, when I first heard of bitcoin I was incredulous. But after many months of research and experimentation I became satisfied that the bitcoin protocols don't have any obvious flaws. God how I wish I could have saved some of that time with a nice summery video. However, far more importantly then bitcoin I want to know why the hell we don't have proof of work as an email spam filter yet!!!!!!

defect 13y ago
There's Hashcash: http://en.wikipedia.org/wiki/Hashcash http://en.wikipedia.org/wiki/Hashcash
new299 13y ago
yep, as you probably know the proof of work idea came from Hashcash which was designed as a spam filtering system. I guess we've all just got locked in to email as it is. Looks like Spam assassin supports it, I wonder if mutt can be configured to support it.
makomk 13y ago
Proof of work as an e-mail spam filter isn't effective protection for two reasons: botnets, and specialized hardware that can compute proofs of work faster than general-purpose PCs.
- joshuak 13y ago
  That would assume that all spammers use botnets or can easily obtain specialized hardware (which are mutually exclusive). It's still a deterrent and makes it non trivial to be a spammer. Also even on botnets each node is large numbers of emails, so it increases the odds that the owner of the infected computer would notice all the work being done. Makers of specialized 'spam' hardware could potentially be targeted by law enforcement easier then dispirit spammers (especially if the hashing algorithm could be designed to be specific to email systems). I can see some arguments as to why it's not 100% effective, but I don't think it needs to be 100% effective to add additional value. That's why I'm amazed it's still not being done. Just like I'm amazed that we still don't have easy to use email encryption, yet demand it for the web (email traffic is far easier to eavesdrop on, and often far more sensitive).
Lerc 13y ago
Given that in the long term the cost of mining bitcoin is in the ballpark of the electricity cost of the proof-of-work (in that being cheaper encourages more people to mine and more expensive means mining would run a loss). You could effectively outsource the cost of the proof of work by having bitcoin validated email. Send a fraction of a bitcoin with an email to let it past. If email clients maintained the wallets you wouldn't need to even worry about the cost if you had a balance of in/out mail. You could still white list anyone you want to email for free. A cost of $0.001 per message would have very little impact on regular users. A botnet would still need to get the funds somewhere to bulk send, if they cracked the mail programs internal wallet they could drain that and send a small number of emails, but beyond that they'd need funds, and quite frankly if they could get at the wallets they'd just take the money direct. It raises an interesting question. what is the value to a spammer of an individual email? The return from advertising/scams/phishing/whatever divided by the number of emails sent. It's got to be tiny.
- jiggy2011 13y ago
  This would incentivise spammers to get people to send emails to them, they could probably do this by signing up lots of fake accounts to services that send registration emails.
- pronoiac 13y ago
  > A cost of $0.001 per message would have very little impact on regular users. I wonder about mailing lists - a couple of thousand members isn't too big a list, but $1 a message adds up. Who pays it? What keeps someone from adding fake accounts to run up the costs of lists they dislike?
  - Lerc 13y ago
    Payment isn't compulsory. You could have a number of mechanisms to clear mailing lists, white-lists would be easiest. Since joining a mailing list should be by user decision, provided the user interface is simple and painless you should be able to include adding to the whitelist as part of that process.
rmc 13y ago
However, far more importantly then bitcoin I want to know why the hell we don't have proof of work as an email spam filter yet!!!!!! Because it's not very useful until nearly everyone supports it. If a non-trivial amount of people don't implement it (which is highly likely when it's first released), then you have to accept non-proof-of-work-emails, or you'll miss the emails. That is the hole in the system that spam will get in through. So why bother supporting it yourself if it won't stop spam?
- joshuak 13y ago
  I disagree. Anything that improves the 'this is not spam' rating is helpful even incrementally. Then once all the email clients support it it's a huge win. Combine that with proper digital envelops (i.e. encrypt all email), and we might finally have a proper email system.
- tomjen3 13y ago
  First of all, adding support for it isn't upto you unless you write an email client. If you are merely a user, you use it if it is implemented. Secondly it is not that spam is a binary thing. You can use proof of work as another feature in your baysian system.

by joshuak 13y ago

defect 13y ago

There's Hashcash: http://en.wikipedia.org/wiki/Hashcash http://en.wikipedia.org/wiki/Hashcash

new299 13y ago

yep, as you probably know the proof of work idea came from Hashcash which was designed as a spam filtering system. I guess we've all just got locked in to email as it is. Looks like Spam assassin supports it, I wonder if mutt can be configured to support it.

makomk 13y ago

Proof of work as an e-mail spam filter isn't effective protection for two reasons: botnets, and specialized hardware that can compute proofs of work faster than general-purpose PCs.

joshuak 13y ago
That would assume that all spammers use botnets or can easily obtain specialized hardware (which are mutually exclusive). It's still a deterrent and makes it non trivial to be a spammer. Also even on botnets each node is large numbers of emails, so it increases the odds that the owner of the infected computer would notice all the work being done. Makers of specialized 'spam' hardware could potentially be targeted by law enforcement easier then dispirit spammers (especially if the hashing algorithm could be designed to be specific to email systems). I can see some arguments as to why it's not 100% effective, but I don't think it needs to be 100% effective to add additional value. That's why I'm amazed it's still not being done. Just like I'm amazed that we still don't have easy to use email encryption, yet demand it for the web (email traffic is far easier to eavesdrop on, and often far more sensitive).

Lerc 13y ago

Given that in the long term the cost of mining bitcoin is in the ballpark of the electricity cost of the proof-of-work (in that being cheaper encourages more people to mine and more expensive means mining would run a loss). You could effectively outsource the cost of the proof of work by having bitcoin validated email. Send a fraction of a bitcoin with an email to let it past. If email clients maintained the wallets you wouldn't need to even worry about the cost if you had a balance of in/out mail. You could still white list anyone you want to email for free. A cost of $0.001 per message would have very little impact on regular users. A botnet would still need to get the funds somewhere to bulk send, if they cracked the mail programs internal wallet they could drain that and send a small number of emails, but beyond that they'd need funds, and quite frankly if they could get at the wallets they'd just take the money direct. It raises an interesting question. what is the value to a spammer of an individual email? The return from advertising/scams/phishing/whatever divided by the number of emails sent. It's got to be tiny.

jiggy2011 13y ago
This would incentivise spammers to get people to send emails to them, they could probably do this by signing up lots of fake accounts to services that send registration emails.
pronoiac 13y ago
> A cost of $0.001 per message would have very little impact on regular users. I wonder about mailing lists - a couple of thousand members isn't too big a list, but $1 a message adds up. Who pays it? What keeps someone from adding fake accounts to run up the costs of lists they dislike?
- Lerc 13y ago
  Payment isn't compulsory. You could have a number of mechanisms to clear mailing lists, white-lists would be easiest. Since joining a mailing list should be by user decision, provided the user interface is simple and painless you should be able to include adding to the whitelist as part of that process.

rmc 13y ago

However, far more importantly then bitcoin I want to know why the hell we don't have proof of work as an email spam filter yet!!!!!! Because it's not very useful until nearly everyone supports it. If a non-trivial amount of people don't implement it (which is highly likely when it's first released), then you have to accept non-proof-of-work-emails, or you'll miss the emails. That is the hole in the system that spam will get in through. So why bother supporting it yourself if it won't stop spam?

joshuak 13y ago
I disagree. Anything that improves the 'this is not spam' rating is helpful even incrementally. Then once all the email clients support it it's a huge win. Combine that with proper digital envelops (i.e. encrypt all email), and we might finally have a proper email system.
tomjen3 13y ago
First of all, adding support for it isn't upto you unless you write an email client. If you are merely a user, you use it if it is implemented. Secondly it is not that spam is a binary thing. You can use proof of work as another feature in your baysian system.