The latest craze in E-mail security appears to be DMARC. Let me preface my post by saying I use DMARC, I use SPF and I use DKIM. I understand that people are mostly up in arms about the importance of DMARC because of how many major organizations haven’t adopted it. I understand it’s importance.
Problems with DMARC
Here’s the issue as I see it. DMARC does not solve phishing E-mails. It doesn’t do much more than SPF already does, and it doesn’t solve trust or identity in E-mail.
DMARC requires compliance by the recipient server to function at all, and all it does is tell the recipient to reject, quarantine, or allow fraudulent E-mails, a feature that SPF already provides.
This prevents someone from sending email from “email@example.com” but it doesn’t do anything to prevent them from sending an email from “firstname.lastname@example.org” which is how a huge number of phishing attacks are launched.
Oh and DMARC gives you some forensic information on who is sending fake E-mails from your domain. Which is completely useless in a high traffic real world scenario because you can’t take any effective action against the perpetrators.
Key Pair Signing & Encryption, a Real Solution.
Meanwhile we have PGP/GPG signatures which would, if properly implemented, provide a user friendly means of identifying the sender of an E-mail and verifying the integrity of an E-mail. But these have been completely disregarded by nearly 100% of organizations as “too difficult” to implement. Seriously, why doesn’t GMAIL come with a ‘PGP’ button?
PGP is arguably easier to implement worldwide than SPF + DKIM + DMARC. All you need to do is create the functionality client-side to create keys manage keyrings and interact with key databases. Compare this with setting up 3 different inline mail verification tools on every E-mail server in the world plus a slew of DNS records which can instruct servers to pass fake E-mails along without notifying the end users at all of suspicion.
Why are we being sold this half-assed solution to E-mail fraud when the real answer has existed for decades and would be easier to implement? If someone can explain why DMARC is being treated as the holy grail of E-mail security I would really appreciate it.
GPG/PGP is “Too Hard” for End Users
Bullshit. The difficulty of PGP/GPG has nothing to do with the technology and everything to do with the lack of proper support in E-mail clients. End Users don’t need to understand the technology at all, they just need a button that creates a key and publishes it to public key databases. The process is no more complicated than adding people to the address book on your phone.
Using keypairs to verify authenticity of E-mail comes with a bonus feature, they can be used to encrypt E-mail to the point that it is “uncrackable”. Adding the signing capability to a service like GMAIL would also make it a lot easier for users to encrypt their E-mail, which would destroy Google’s business model since they read all of your E-mail to gather data. This is probably the #1 reason why keypairs have been ignored, with the #2 reason being pressure from world governments.
My paranoid conclusion is not the only possible scenario, I would love to hear the opinions of other internet security experts on this issue.
Some Good News
You can implement PGP/GPG in your own E-mail and start using it with your friends, family and colleagues right away. And you should. Visit the Electronic Frontier Foundation website to find some simple step by step tutorials for all platforms.
My Public Key: https://tailpuff.net/keys/