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An idea for stopping spam

By PresJPolk in News
Tue Jul 18, 2000 at 08:43:17 AM EST
Tags: Internet (all tags)

After reading the article about ORBS, I started thinking about trust on the internet. People who use systems like MAPS RBL and ORBS rely upon trustworthy third parties to mediate access to their email accounts.

What if we stopped spam by using a different trust model?

PGP already has a known, studied trust model. What if mail servers were made aware of OpenPGP signature schemes, and rejected mail that wasn't signed by trusted keys?

Spammers would not want to put their name behind individual pieces of email, because that would leave them vulnerable to legal action.

Of course, the details of what keys to trust would be difficult. One would probably end up having to trust a third-party anyway: Keyservers would maintain lists of keys that are known to be held by certain people or organisations. However this scheme would have advantages over IP address-based systems like RBL or ORBS:

  1. Messages signed by good keys can be traced to the sender, for possible legal action.
  2. RBL and ORBS can be circumvented by moving to a new subnet. New trusted keys cannot be made so easily.
  3. Key-based validation allows for known-good people to send emails from anywhere, even from a bad ISP, or a service like Hotmail. Hotmail-like services provide a good backup communications route in case of service outages.
  4. The requirement of signatures would provide motivation for more people to learn, and use, PGP-like systems. Widespread use of encrypted communications would almost certainly follow.

Does this idea strike other kuro5hin readers as interesting enough to study? Has anyone else tried this before?


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An idea for stopping spam | 19 comments (16 topical, 3 editorial, 0 hidden)
Anonymity and free speech. (5.00 / 4) (#1)
by aragorn on Tue Jul 18, 2000 at 06:29:17 AM EST

To me, this seems like a slippery slope. In many cases, anonymity is key to free speech. If you can't say something without the fear of retribution, your freedom to speak your mind is greatly decreased. Don'e misunderstand me, though. Taken alone, I think this sounds like a good idea. It's just that I'm concerned about where it could lead if extrapolated to content on the 'net in general.

Re: Anonymity and free speech. (5.00 / 1) (#5)
by PresJPolk on Tue Jul 18, 2000 at 06:50:03 AM EST

First off, I love the social pressures that anonymity brings.

I don't want anonymous people to have access to *my* email account, though. If you want to say something anonymously, say in on kuro5hin, or go get a geocities web page, or spend 32 cents and mail it to me. Don't make *me* pay for your speech, though, which is what you're doing if you mail it to me.

[ Parent ]
Re: Anonymity and free speech. (5.00 / 1) (#7)
by Tin-Man on Tue Jul 18, 2000 at 10:38:44 AM EST

Man, it's been a while since you've used snail mail, hasn't it?

Last I checked, the price for first-class postage in the US was 33 cents.

The future sure isn't what it used to be!
[ Parent ]

Re: Anonymity and free speech. (none / 0) (#10)
by Anonymous Hero on Tue Jul 18, 2000 at 12:52:54 PM EST

This has nothing to do with free speech. It's about us refusing to read mail from people we don't trust. Where does free speech come into it?

[ Parent ]
The only problem I see with this... (5.00 / 1) (#6)
by Inoshiro on Tue Jul 18, 2000 at 08:44:45 AM EST

is that currently, there are no checks on who puts keys onto the public keyservers. I could make up a keypair for John Q. Public, and post it to the place. Then I could go sign as John Q. Public and send it along to thousands of people.

Granted, this might allow easier tracing, but currently the mail being sent around the 'net has a nice trace in the headers which is fairly accurate.

IMO this would be better used for the transparent end to end encryption of mail (ie: when I send mail out, it checks the public keyservers if there'd a PGP key for the to: email address, and encrypts it with that... and at the receiving end, it sorts unencryped and encrypted mail into different folders, and verifies signatures/decrypts mail for the end user).

[ イノシロ ]
Re: The only problem I see with this... (none / 0) (#16)
by Anonymous Hero on Wed Jul 19, 2000 at 04:41:45 PM EST

The only problem I see with this... is that currently, there are no checks on who puts keys onto the public keyservers.

We need to be able to prove who we are electronically, but only when we want to.

We need an authority to create and maintain public keyservers for dealing with financial transactions and legal contracts, between businesses and citizens. Any key that has been signed by this authority can be trusted to be valid. If we receive e-mail from someone who cannot be verified via this key server, we can choose to filter it out, or in the least, we will be hesitant to trust the content of the communication.

Who should be this authority? Perhaps your government? Perhaps your bank? Perhaps a new organization with global power.

Should all currencies be used in this system, and conversions be inherent? Or, instead, should a single global currency be put in place?

We do not need to get rid of non-electronic authenticated methods of monetary transfer, including cash.

We need to maintain the right to create alternate public/private key pairs for our personal privacy.

The trick to this will be ensure that no one can fake the authority's key and to ensure that it is made strong enough and replaced often enough that we can be sure that no one has had anywhere near enough time to crack it.

[ Parent ]
Re: The only problem I see with this... (none / 0) (#19)
by Anonymous Hero on Thu Jul 20, 2000 at 12:00:32 PM EST

We need to be able to prove who we are electronically, but only when we want to.

So *everyone* has a key. The only people who don't are criminals and spammers. How long before you have to present said key at every frickin website you go to?
john doe: But I don't want to give you my key.
Website Well, you must be a criminal and we don't want your trade/custom anymore

Who should be this authority? Perhaps your government? Perhaps your bank? Perhaps a new organization with global power.

Go read 1984

[ Parent ]
Web of trust (none / 0) (#8)
by cesarb on Tue Jul 18, 2000 at 12:04:01 PM EST

This could be used together with a PGP-style ¨web of trust¨ -- I have a key, Alice signs it, and Bob signs Alice´s key. Then Bob knows I exist (since he trusts Alice) and can receive my email. Nowhere there is a need to know that my key corresponds to the person named ¨cesarb¨, only that it´s from a legit person and not from a spammer (since Alice wouldn´t sign my key if I was a spammer).

So let´s suppose Carlos has signed a spammer´s key. Lots of people would sign the spammer´s key as ¨bogus¨ (sorta third-party revoke). If Carlos does it again, his key would be signed as bogus too. He would not receive another key, since giving him a new key would be begging to have your key flagged as bogus. Being able to sign a ´bogus´ signature as bogus would also be needed.

The (partial) anonymity comes from the fact that only the one who signs a key needs to know who the key´s owner is.

Re: Web of trust (none / 0) (#9)
by Nygard on Tue Jul 18, 2000 at 12:11:04 PM EST

A web of trust turns out to be pretty easy to corrupt or subvert. All it takes is one person willing to sign a spammer-signer's key for some consideration ($50, $50k, free diet pills, whatever). Then that spammer-signer can sign actual spammer's keys.

[ Parent ]
Re: Web of trust (none / 0) (#11)
by cesarb on Tue Jul 18, 2000 at 02:08:19 PM EST

If anyone does it, and it´s discovered (after some time it´ll get pretty obvious), that person would end up blocked.

[ Parent ]
I love you, Melissa B. Toklas (3.00 / 2) (#12)
by Anonymous Hero on Tue Jul 18, 2000 at 03:38:38 PM EST

So, in the ideal Email World of Tomorrow, everyone would have their own PGP key, and a web of trust would be built up through me signing your key, then you signing his key, and him signing her key, and so on and so on...

Until the next Melissa virus seizes control of Lookout Undress (or whatever the dumbed down MUA of the future is), signs it's key with yours and forwards itself to everyone in your address book (or better yet, just steals a signed key and sends that home, not drawing attention to itself at all), bringing the entire web of trust crashing down around us

It's a nice thought, but you have to consider that a large portion of computer users really don't care about best security practices, or how technology really can improve their lives instead of just saying it will, or whether their actions are just making everything that much worse for the rest of us.

And many of these people write software that the rest of them use. Until you design a solution with everybody in mind, not just the clue-enabled, it will never truly work.

Just my $0.02 (Canadian, plus GST and PST, bulk discounts apply for the truly cynical)


passphrases (none / 0) (#13)
by thomas on Wed Jul 19, 2000 at 04:15:22 AM EST

umm... usually you have to enter a passphrase before you can access a key. And quite frankly, people who have computers powerful enough to brute-force a half-decent passphrase in any reasonable length of time, probably aren't running MS-Outlook as an email client on that particular machine.

Of course, that said, it might be possible for someone to write a virus which distributes the passphrase-cracking process across all the infected machines.

oops... don't tell the NSA or CIA I said that... they might decide to anonymously create such a virus as a snooping tool :-(

War never determines who is right; only who is left.
[ Parent ]

Re: passphrases (none / 0) (#14)
by Anonymous Hero on Wed Jul 19, 2000 at 02:20:51 PM EST

Umm... Why use brute force when you have VBScript?

Perhaps my wording was a bit off -- I'm not proposing the easy theft of a user's private key via an email worm, but rather that unauthorized _use_ of that key.

Suppose we have an email client (let's call it "Lookout", or "Post-it Notes" for want of a better name). It has been designed to sign all outgoing email with the user's private key. So, it _needs_ to have access to that key. The user may have to enter a passphrase when the program starts, but I wouldn't expect it to be required every time the key is used. (How often do Outlook, Netscape Messenger or Lotus Notes actually ask for a password? Only once. Sometimes not even that. Why is that? Because users are lazy, and they demand features like that.)

Once the email client has the power to sign and send mail (or sign keys, or pick lottery numbers, or use any other Innovative Feature[tm]) with the user's key, we don't _need_ to brute force anything. Especially if it has a built in scripting language which provides functions like VBDisableAllSecuritySettings, VBSignAndSendMessage or VBRunNoSmokeDotBat.

So yes, using PGP means that I can have some certainly that a message signed with your key came from your computer but in a world with "Melissa's Pen Pal Loves Good Times", I can't trust that any key signed by you actually belongs to someone you know or that an email from your computer was actually sent by you, so that whole "web of trust" starts to fray around the edges, leaving things not much better than they are now.


[ Parent ]

Anonymous free speech SEE: UNIBOMBER (5.00 / 1) (#15)
by Anonymous Hero on Wed Jul 19, 2000 at 02:59:31 PM EST

Free speech has always meant that you are free from retribution. However, it has nothing to do with being anonymous. In ye olde times, a person would talk in public. It was free speech. Certainly you knew who was talking, and could always follow them home. You can also write anonymous letters, but as we saw with the Unibomber, that doesn't always keep us anonymous either.

Make ISPs responsible (none / 0) (#17)
by www.sorehands.com on Wed Jul 19, 2000 at 08:11:29 PM EST

No one is truly anonymous on the web.

Require an ISP to take a credit card number or deposit. Now, if someone uses the account for spamming, the ISP would be able to charge the violator.

Also by allowing Spammers to be sued, and with statutory damages (meaning that you don't have to prove actual damages to get a statutory amount).

This would then add a cost to spamming, which eliminates the no cost advantage spamming

Also, get the FBI to prosecute spammers who hijack servers.

Mattel, SLAPP terrorists intent on destroying free speech.

The solution is simple: make people pay you to rea (none / 0) (#18)
by TheDullBlade on Thu Jul 20, 2000 at 01:21:26 AM EST

Charging a dime makes mass spam infeasible. If you are constantly pestered by lamers, you can filter them out by gradually raising the price. After all, you can always return the money if they give you a good reason.

This place actually provides this service right now.
Visit Boswa Bits, now with 99% less evil!

An idea for stopping spam | 19 comments (16 topical, 3 editorial, 0 hidden)
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