What to know about ads.cert

Industry experts gear up for the adoption of Ads.cert, the next stage of the IAB's fraud fighting initiative, ads.txt.
Markus Spiske Unsplash

A new year will likely mean the launch of a new fraud fighting initiative by the Interactive Advertising Bureau (IAB). Another solution to one of the most talked about issues in the digital media industry – a more secure programmatic bidding process – is set to come in 2019. Ads.cert, the second stage of the  IAB’s attempt at cleaning up the supply chain, is currently in development via the bureau’s tech lab.

It’s a continuation of ads.txt, a fraud-fighting text file developed by the IAB Tech Lab in 2017. Ads.txt displays a publisher’s legitimate, authorized ad inventory sellers. The page is available publicly. Canadian publishers such as Sportsnet, HuffPost and the Toronto Star have adopted the file.

Ads.cert, however, goes a step further to ensure the authenticity of those sellers.

Patricia Gray, VP of digital media systems at Media Experts, told MiC the new extension is “an evolution of transparency and accountability that is cleaning up the programmatic exchange inventory and sellers.”

She says that although ads.txt was a step in the right direction, “Adoption rates remained low and bad actors found a way to trick legitimate publishers into adding them to their ads.txt list. This necessitated the roll out of ads.cert, which forces bid requests to be authenticated and encrypted.”

(According to measurement site FirstImpression.io, Canada’s adoption rate sits at 35% for the country’s most popular 500 sites, and has been flat since April. As of Oct. 3, it ranks at #18 for adoption rates among countries. The highest adoption rate is 40% for the U.S.).

According to Ian Trider, director of RTB platform operations at Centro, it has always been known that ads.txt was just the beginning, with the two initiatives developed to work in tandem rather than compete.

Speaking with MiC, Trider describes ads.cert as part of the bigger journey to ensuring that the integrity of the supply chain can be confirmed to advertisers, addressing the problem of fraudulent entities that claim (falsely) to sell inventory without buyers being able to verify.

“Ads.txt represented the first step in that journey,” Trider says, “because there’s never a final step when it comes to addressing quality and fraud.”

However, he says this is a way for buyers to ensure that impressions are what they say they are, come from where they were supposed to come and are from who they are supposed to be from.

“It uses public key cryptography similar to the way your web browser determines that a website is secure,” Trider says. “When a publisher has an impression that they want to sell, they will compose a digest, a short message of certain key details about that impression.” That message may include the domain, a user’s IP address, or any other info that might appeal to a “bad actor to spoof,” according to Trider.

The next step is for publishers to sign the message with a private key, which flows into one of the ad exchanges, eventually arriving at the buy side where it is possible to use a publisher’s public key to confirm the signature’s authenticity.

“If somebody in the middle changed some detail, it would no longer verify when you tried to check the signature was valid, and you would know that you have an impression that’s been tampered with,” Trider explains, adding that it’s a complex process. “There’s a lot more nuance involved in this one [than ads.txt], so it’s important to get it right,” he says.

Right now, ads.cert is part of the OpenRTB 3.0 framework, which is an upgrade of the current 2.5 framework that, when adopted, requires exchanges, SSPs and demand-side platforms to convert over.

“I expect to see a future in which the demand side would simply refuse to buy unsigned impressions and would refuse to buy traffic if the impression signature does not validate,” says Trider, adding that he expects that the industry may start seeing early adoption in late Q1 2019.

However, Sonia Carreno, president at IAB Canada, told MiC that the initial specs – currently in the initial public commentary stage – need to be finalized, before which “there will be no immediate push for adoption.”