AdLedger Consortium Is Building a Tool to Protect Bidstream Data

Lawmakers have been calling for investigations into ad-tech practices

AdLedger was founded in January 2018 by IBM, Tegna and MadHive Getty Images
Headshot of Andrew Blustein


Digital advertising consortium AdLedger has a new open standard it hopes will solve some of programmatic’s ills.

The nonprofit consortium has created what’s essentially an encrypted digital signature, called CryptoRTB, that can be inserted into bid requests. During a real-time ad auction, this would allow publishers to encrypt specific information, like a user’s IP address or location, and only share that data with specific partners.

Christiana Cacciapuoti, executive director at AdLedger, said the technology, which is built on blockchain and cryptography, would help create a more “intimate relationship between the publisher and the advertiser.”

“We’ve never had an opportunity as an industry to create a technical parameter … where people can’t manipulate what is in ad request,” Cacciapuoti said. “What we’re trying to do is create a world where we can encrypt data instead of having everything be readable.”

Publishers have complained about data leaking out of the digital advertising bidstream. Now lawmakers are calling for investigations into the practice, since it eats into publishers’ revenue and allows for unsavory user profiling based on race and religious beliefs.

CryptoRTB sits in the extension field of the OpenRTB protocol. The extension field is a free form macro, essentially an empty box where a stakeholder can insert whatever data related to the bid request they like. Cacciapuoti said that field typically remains empty during bid requests.

A digital signature of the participants of the ad auction is created, along with certain claims about the auction, like the size of the ad, details of the end user and the domain it will run on.

Cacciapuoti said this protocol will help address fraud, transparency and privacy by creating a “chain of custody” of who is involved in the ad transaction.

Members of AdLedger are already testing the technology. Participants include GroupM, Omnicom Media Group, Publicis Media, The Hershey Company and Meredith. The consortium was founded in January 2018 by IBM, Tegna and technology company MadHive.

It is free for publishers, agencies and brands to join AdLedger. Cacciapuoti, who is also vp of partnerships and platform operations at MadHive, and AdLedger board members do not take a salary for their roles in the consortium.

Technology companies must pay dues to join AdLedger, and they do not get a vote in consortium activities. The group’s philosophy is that tech companies need to invest in disrupting themselves before outside groups, like lawmakers or Big Tech, do.


Andrew Blustein is a programmatic reporter at Adweek.