Coming on the heels of ads.txt, is ads.cert — the latest Interactive Advertising Bureau (IAB) Tech Lab specification designed to combat ad fraud. The specification’s official name is Ads.cert: Signed Bid Requests and was released as part of OpenRTB 3.0.
At a high level, ads.cert offers inventory assurance, giving buyers peace of mind that the inventory they purchase is correctly represented in the bid request. Ads.cert exposes if any details from the original ad request were modified at any point in the supply path, assuring buyers that the information included in the bid request is accurate. For example, if the placement site or device type was modified and maliciously misrepresented, ads.cert would allow the buyer to see that this field had been tampered with.
Ads.cert works by using a cryptographically signed bid request to offer a authenticated path back to the inventory source. This path allows buyers to verify and validate that the contents of the bid request are accurate and haven’t been modified. Let’s take a look at how this would work:
- The publisher generates two keys — one private and one public. The private key is known only by the publisher and the publisher’s approved ad system. The public key can be viewed by anyone and is hosted on the publisher’s website, for example at www.publisher.com/ads-cert.txt.
- The publisher sends an ad request to their SSP.
- The SSP uses the publisher’s private key to add an encrypted signature to the bid request.
- When the DSP receives the bid request, they utilize the publisher’s public key to authenticate that the contents of the bid request have not been modified.
Does ads.cert replace ads.txt?
No, the two specifications complement each other, providing inventory assurance and the IAB Tech Lab recommends that they be used in conjunction. Where ads.txt authorizes the seller’s rights to a Publisher’s inventory, ads.cert authenticates that impression opportunities on that inventory are accurately represented.
Imagine you were buying a Rolex from a watch store. You would want to make sure that both the store was affiliated with Rolex and that the information about the watch — such as when it was made and what materials were used — was accurate.
The same is true in advertising; buyers want to ensure they are purchasing inventory from a reputable source and that the details of the inventory are accurately represented.
When will the industry start using ads.cert?
The public comment period for ads.cert closed in September 2018, and the IAB is currently reviewing the comments and working to generate a final version of the specification. According to the IAB, they hope to have a final specification available by the end of 2018.
Industry-wide adoption of ads.cert, however, is also dependent on adoption of OpenRTB 3.0. While OpenRTB 3.0 offers many advances for the industry, it is not backwards compatible with previous versions of the specification, which could cause a delay in adoption.
Here at SpotX, we’re excited for both OpenRTB 3.0 and ads.cert because both specifications mark major advancements for the industry. Whether you’re an advertiser or a publisher, we encourage you to keep an eye out for the IAB’s final release of the OpenRTB 3.0 specification.