[Cryptography] Paid SMTP (PSMTP)

[Bertrand Mollinier Toublet]

> On Feb 27, 2018, at 05:15, Ersin Taskin <hersintaskin at gmail.com> wrote:
> 
> I received some remarks and challenges to my proposal for PSMTP. Some through the mail list, some in private. I researched the anti-spam state-of-the-art on the web. I checked patents, implementations, services, products, techniques, etc. 
> 
[…]
> 
> Therefore, the proposed scheme is robust and effective because it is simple, fair and secure. The higher asymmetry brings enough room to find the right value for CommCoin to kill spammers with low or no cost to honest agents. Its simplicity can make it to the SMTP protocol in the long run.
> 
Ersin, a few thoughts, although it seems hardly fair to burden the Crypto mailing list with what is essentially a spam fighting discussion (moderators will decide):

a) can I ever get to a point where I can outright reject non-paid email, as a receiver, and not miss out on potentially desired mail? If not, this solution suffers from one of the FUSSP issues whereby it needs to be fully deployed to be of value.
 In fairness, you do acknowledge this problem (even though you are not providing a solution to it)

b) does being a sender require a TEE? If so, this is a major impediment, because deployment of the solution is effectively akin to deployment of new hardware.

c) if I don’t require a TEE, then I’m subject to theft of the sender payment, which is a strong counterincentive to deploying the solution in the first place: as a sender, I would not want to take on the potential liability of a spam run executed by stealing my payment credentials.

d) how are both the recipient and "the IETF” getting paid in this scheme?


Finally, and even though you seem to be of good faith in your presentation of PSMTP, I would refer you to the following couple of “You might be” entries:

https://www.rhyolite.com/anti-spam/you-might-be.html#e-postage
https://www.rhyolite.com/anti-spam/you-might-be.html#critical-thinker
https://www.rhyolite.com/anti-spam/you-might-be.html#senior-IETF-member-5
https://www.rhyolite.com/anti-spam/you-might-be.html#programmer-4
https://www.rhyolite.com/anti-spam/you-might-be.html#programmer-6
https://www.rhyolite.com/anti-spam/you-might-be.html#spam-fighter-4

While they are writing in the acerbic tone of a battle-weary spam fighter, there is sound advice behind them and I would like to encourage you to ponder their wisdom.
-— 
Bertrand