Home / Blogs

Searching for Truth in DKIM: Part 3 of 5

Don't miss a thing – sign up for CircleID Weekly Wrap newsletter delivered to your inbox once a week.
J.D. Falk

Last year, MAAWG published a white paper titled Trust in Email Begins with Authentication [PDF], which explains that authentication (DKIM) is "[a] safe means of identifying a participant-such as an author or an operator of an email service" while reputation is a "means of assessing their trustworthiness."

Reputation systems based on IP addresses, including Return Path's Sender Score, are used by many ISPs and anti-spam vendors to determine which mail to accept, which to reject, and which to subject to additional filtering before making a delivery decision. There, the identifier is the IP address.

The reason this sort of reputation works for delivery decisions is that it's an attempt to predict whether the sender of a message can be trusted to send mail that the recipients want — or, more accurately, whether the IP address of a message can be trusted to send mail that the recipients won't complain about. We also mix in the concept of safety, largely in the form of how likely it is that the IP address is sending phishing scams or similar bad stuff.

In part 1 of this series, we described how the DKIM "d=" identifier brings us closer to knowing who sent a message, because it can be tied to the company or person who registered that domain name.

Reputation or certification based on the DKIM d= identifier will have the same goal — and will be more effective, because it will be tied to the signing entity rather than a single IP address. When ADSP is applied, that signing entity could be the author domain (see part 2). If not, it's still a useful method for determining whether to trust the message. Any d= domain who regularly signs trusted messages becomes trustworthy, and vice versa.

Plus, d= reputation is portable — the owner of the d= domain can use that same identifier on multiple IP addresses, even bringing it to a different ESP (as we described in part 2), without having to start over from scratch or to "warm up" IPs.

While not absolutely perfect, reputation and certification based on d= will be far more accurate, effective, and convenient than when it's based solely on the IP address. But, does a trustworthy d= domain indicate a truthful message? Stay tuned for part 4.

(This article was originally published by Return Path)

By J.D. Falk, Internet Standards and Governance. More blog posts from J.D. Falk can also be read here.

Related topics: Domain Names, Email, Cybersecurity, Spam

 
   

Comments

To post comments, please login or create an account.

Related Blogs

Related News

Explore Topics

Dig Deeper

Afilias Mobile & Web Services

Mobile Internet

Sponsored by Afilias Mobile & Web Services
Afilias

DNS Security

Sponsored by Afilias
Verisign

Cybersecurity

Sponsored by Verisign

Promoted Posts

Now Is the Time for .eco

.eco launches globally at 16:00 UTC on April 25, 2017, when domains will be available on a first-come, first-serve basis. .eco is for businesses, non-profits and people committed to positive change for the planet. See list of registrars offering .eco more»

Boston Ivy Gets Competitive With Its TLDs, Offers Registrars New Wholesale Pricing

With a mission to make its top-level domains available to the broadest market possible, Boston Ivy has permanently reduced its registration, renewal and transfer prices for .Broker, .Forex, .Markets and .Trading. more»

Industry Updates – Sponsored Posts

The Rise and Fall of the UDRP Theory of 'Retroactive Bad Faith'

.PRESS Supports Press Freedom Day for 3rd Consecutive Year

Leading Internet Associations Strengthen Cooperation

5 Afilias Top Level Domains Now Licensed for Sale in China

Radix Announces Largest New gTLD Sale with Casino.Online

2016 Year in Review: The Trending Keywords in .COM and .NET Domain Registrations

Global Domain Name Registrations Reach 329.3 Million, 2.3 Million Growth in Last Quarter of 2016

A Look at How the New .SPACE TLD Has Performed Over the Past 2 Years

Verisign Releases Q4 2016 DDoS Trends Report: 167% Increase in Average Peak Attack from 2015 to 2016

Verisign Q3 2016 DDoS Trends Report: User Datagram Protocol (UDP) Flood Attacks Continue to Dominate

2016 U.S. Election: An Internet Forecast

Government Guidance for Email Authentication Has Arrived in USA and UK

ValiMail Raises $12M for Its Email Authentication Service

MarkMonitor Supports Brand Holders' Efforts Regarding .Feedback Registry

Don't Gamble With Your DNS

8 Tips to Find Your Perfect .COM Domain Name

Why .com is the Venture Capital Community's Power Player

Defending Against Layer 7 DDoS Attacks

Understanding the Risks of the Dark Web

New TLD? Make Sure It's Secure